Staying at the Ritz in Mexico City now, and I've been here long enough to make give some feedback:

Pros:
1) Clearly the best overall hotel in Mexico City now. The construction is high spec (and higher spec than anything else I've seen in Mexico City).
2) Design is very contemporary, so you might feel like this is missing a lot of that cultural influence that you might come to expect at other establishments. You could get this experience in any other city.
3) This is a Ritz, but among the best Ritz's I've stayed at. I've stayed at many, and they've all been awful with sole exception of Kyoto.
4) I stayed in a Junior Suite with terrace. Windows are truly floor-to-ceiling. Finishes are good but the hotel is also brand new. A lot of high tech gadgetries fitting of a 5 star hotel.
5) Front desk staff were great. There were some service lapses, but good recovery in all.
6) Food in the hotel restaurant is great, although regrettably not that local (except for the breakfast). Breakfast has a lot of Mexican dishes and they're great. But lunch is very nondescript Western. The food was still great. Drinks are good.
7) the views are so good. if it wasn't for the smog, the view of chepultapec park makes you feel almost like you're in Tokyo.
8) loved ling ling, which is not technically in the hotel (and you can't bill to the hotel), but it's in the same building. And I normally despise hackassans. It's basically hackassan with Mexican influences, but I love the way they blend the flavors.
9) Love the dyptique amenities.
10) Bed is incredible.
11) TV has Netflix and YouTube integrated. Awesome! But you have to sign into Netflix...

Cons:
1) the bathrooms. love the fit and finish... but the shower room smelled. in general, the hotel has not so great smells. they should really invest in scents. recall that the four seasons in Florence has dr. vranjes dotting the entire lobby and floral arrangements abound.
2) sticking to the bathrooms... love the marble everywhere but this is where you can find cost-cutting. the sub-room (shower, toilets) are in very slightly irregular shapes... you can tell they were aiming for rectangles but some of the corners are clearly not right angles. Yes, I notice this stuff.
3) lighting in the bathroom is poor even at the highest setting. It didn't bother me but I can see it bothering many others.
NB: For some reason bad bathrooms has been my issue at all Mexico hotels and even high end airbnbs. Not particularly clean or high spec. This is the highest spec bathroom I've been in in Mexico, but it's still maybe a 6/10 compared to other hotel bathrooms (my points of reference: La Reserve, the Crillon, Amanzoe, Nobu Malibu Ryokan, Villa La Coste, Ritz Kyoto, Claridges (post-renovation), higher end suites at Four Seasons Florence).
4) prior reviews mentioned that water seeps out of the shower and floods the bathroom and room. it seems like the hotel recognized this critical design flaw and hastily installed a pseudo-marble barrier between the shower and the rest of the bathroom. It works, but it clearly doesn't match the marble underneath, so it looks cheap.
5) The electronics in the room don't always work that well and they're inconsistent. For instance, the black-out light doesnt black out the toilet's lights, so if I accidentally left them on I had to leave the bed to shut them off manually. I ran into my suitcase ont he way back to my bed because then the whole room was pitch dark.
6) The layout of my suite wasn't particularly good. Plenty of room, very much misused.
7) Lack of attention to detail in cleaning--I found a solitary pube in the shower room when I checked in. That really turned me off. Then again it's so dark I wouldn't be surprised if housekeeping just couldn't see it.
8) I suspect due to lack of attention to detail and some of the materials being high spec but not amazingly high spec, the hotel will really start to show wear in less than a year. It's a shame that it might feel due for a renovation in less than a year. By contrast, I've been staying at the Crosby Street Hotel at least annually for about a decade and I don't think they're anywhere close to needing a renovation. I actually don't know how CSH does it given the amount of carpet throughout. You'd expect that to start smelling/showing some serious age 10 years in.
9) Not all staff speak English that well. This means that in the restaurant you're not 100% sure they got your allergies right so you have to confirm about 20 times (and to their credit we had no issues with compliance once we were understood). Room service would occasionally get an order wrong but would fix it if you explained it. I thought my thermostat wasn't functioning (but it turns out it de-activates when the sliding doors aren't fully shut), but the technician couldn't understand what I was saying.

I'm sure I'll have other random thoughts as my stay progresses, but my initial views are above.