I really liked the hotel a lot; it might even have unseated the W Hong Kong as my favorite city W*. Yes, there are still annoying W things about it, but perhaps what I liked most was that unlike many Ws which feel like they slapped some unusual paint color designs on an otherwise basic hotel, many parts of this one actually felt like a high-end boutique hotel. The design of many of the public areas is really lavish and beautiful IMO, and all the more so to fit into a city with such a distinct style as Amsterdam (though it helps that one of the two buildings the W took over was not one of Amsterdam's most beautiful, to say the least, already).

In particular, the Exchange building's elevators had a cool glass-walled design (inside an otherwise enclosed elevator shaft), the top floor of the Exchange building (home to check-in and the restaurant and bar) has a beautiful glass-walled design with panoramic views over Amsterdam in most directions, and the Bank building is a stately older building on its own with some nicely done restorations and adaptations.

I stayed in the Exchange building and didn't mind the busy-ness of it, though Bank was definitely quieter. There was an event in the Exchange lobby lounge one evening and it definitely would have been tiring to have arrived for check-in while loud music was going nearby; I could imagine the Exchange elevators also sometimes get tied up with people going to the bar and restaurant on the top floor though we didn't run into any problems with it, but we also weren't there on a Friday/Saturday evening.

(*In case anyone wants to debate, my sample set is: NY-TS, both CHI, BOS, both MIA, AUS, MSP, SEA, SFO, LAX-Westwood, YUL, MEX, LON, IST, HKG.)

Location

First of all, the location is about as good as you could hope for, with all of central Amsterdam within a half-hour walk. There are also a number of trams nearby if you don't want to walk as far, and the new Rokin station on the Metro isn't too far. Central Station is just about walkable, though it wouldn't be ideal with any amount of luggage since most of the sidewalks are somewhat bumpy.

Uber is also a convenient option, and I used it without much trouble both to and from AMS.

Room

I used SNAs which cleared in advance to a Cool Corner Room, which is notably not a suite, nor was our room actually in the corner of the building, so top marks for incoherence there. (At least that has been the SNA category at this hotel for some time, AFAIK, so it's not like all the Marriott properties that have started offering SNAs to deluxe rooms and the like.) And for that matter, the room did offer the larger sized Bliss toiletries that are common in W suites outside North America, so in that sense it is a suite, I guess.

Regardless, I was happy with the room and would gladly use SNAs here again, especially since I have heard from other reviews that the standard rooms are quite small and the hotel is not otherwise forthcoming with upgrades. 

A picture of most of our room:

A few things about the room:

First, yes, that is a bathtub directly behind the bed. Practical? Not especially. But it didn't bother me. I sometimes think W Hotels do do things like this for same reasons that Abercrombie and Fitch stores in malls used to keep the lights low and the music loud (in that case, to keep the target teenage demographic's parents outside). 

But second, the room was otherwise spacious, had big windows, and was reasonably well-thought-out for a W, with fairly comprehensive light controls by the door and bedside, a good vanity mirror set-up. Shower was lovely with a powerful rainfall showerhead and handheld sprayer, with comprehensive and logical controls. Decor was a bit stark, but still felt cohesively designed to me (unlike the W London, which also featured a lot of concrete and in some ways a similar room design but there just felt done on the cheap). Complementary water bottles were also replenished daily.

Third, note a few drawbacks for specific use cases: there isn't much by way of desk space so it's not great for working, though there is a desk of sorts built into the foot of the tub, next to the sink and behind the bed (surely that is the relative position of the desk in all your hotel rooms?). The lighting setup is not great if for example one person likes to read for a while as the other goes to sleep, as there isn't really anything for a traditional bedside reading light. And while you could just about make it work sharing the room with someone you're not intimate with -- there is a bigger sliding door that closes off the area outside the shower door, and the shower and toilet are fully and opaquely enclosed -- it wouldn't be ideal. Oh, and the TV is in an odd location (about directly behind me from where I was taking the photo); it does swing out on an arm but it's still at an awkward angle from the bed and not really watchable from the sofa.

Platinum Breakfast

The Platinum Breakfast treatment was one of the best parts of the stay. Like many of the high-end SPG hotels in Europe, there was a solid buffet on offer, but what truly set it apart was two features: first, in addition to the buffet, you were able to order from a fairly extensive menu of made-to-order dishes, included as a Platinum member; and second, both of the venues for breakfast were beautiful: either Duchess in the Bank building, in a grand old high-ceilinged space which has been beautifully and gently modernized, or Mr. Porter on the top floor of the Exchange building, with the aforementioned glass walls and sweeping views. 

The offering was more or less the same between both, though it's definitely worth trying both (and you are welcome to eat in either, regardless of which building you're staying in) if you're staying more than one night, both for the different settings and because the offering is slightly different -- Duchess had a more extensive selection of made-to-order dishes while Mr. Porter had a slightly bigger buffet.

At both there was also a very large selection of fresh-squeezed juices, as well as Prosecco at the buffet.

Some pictures of the buffet space at Duchess (sorry I didn't get the same for Mr. Porter, but the food offerings were similar):

(Sorry about the sideways photo above and especially those below, can't figure out how to fix it...)

Then here was the menu at Duchess -- the "Duchess breakfast experience" is what's included for Platinums and otherwise costs 35 EUR per person:

And then here was the shorter made-to-order menu at Mr. Porter:

The quality of everything was very good, though I guess I should mention that to my American tastes, the bread they used for the base of the eggs benedict and similar dishes wasn't great, though I saw similar things elsewhere in Amsterdam so I think it's just the Dutch style.

In each restaurant we were presented a zero balance receipt to sign, and left a few Euros tip with the signature.

Spa

We did get massages at the spa, which weren't outstanding but were decent and were fairly reasonably priced for a major European city IMO. Advance bookings are worth it, especially to guarantee exact service types or technician preferences.

The spa itself is quite impressive though, integrated in and around the old vault in the Bank building.

I didn't get a chance to use it but the gym in the Bank building also looked fairly nice. Not huge but a good size for the size of hotel and for Amsterdam, and with a nice street-level view over the canal behind the Bank building. It did seem that apparently locals can buy a membership for the gym, which was surprising because it really isn't that big, but I don't know how many other gym options there are in central Amsterdam. So that could possibly create crowding at peak times, not sure.

Service

I didn't have any major service needs on this trip so I can't comment for sure, but overall I thought the service was fairly good, and not chilly as is sometimes complained of some Ws (including this one further upthread IIRC). The front desk was friendly enough though certainly not overly warm -- I didn't ask but there certainly wasn't any additional upgrade forthcoming, nor any special effort to help with an early check-in when we arrived at noon. (They said they would call when the room was ready, and did not, though when we got back at 3:30 the room was available.)

Other staff around the property were generally quite friendly, including restaurant and bar staff, doormen, and spa staff.

I also contacted the concierge ahead of time asking for a restaurant recommendation for Monday night in particular, when many nicer Amsterdam restaurants are closed, and I thought it a little tacky that they suggested their own Duchess restaurant (alongside Rijks, at the musem, which we ended up going with), though I did later discover that it actually is a pretty good restaurant, so maybe not so outrageous.

Overall

I'd happily stay here again on another vacation trip if I could swing the price, which isn't cheap, though is probably still a decent deal for the quality of the hotel and the location. (Though I also paid for a very small standard room which I was upgraded out of as well; I might feel differently without the upgrade.) I'm sure at some times of year points may be a decent value here, though for my dates it would have been a pretty poor use of points.