Somewhat belated review so some of the details may be a little hazy, but in general I enjoyed this new addition to the SPG options in Jakarta. 

I arrived in late-Jan for a 2 night stay on an opening offer rate of IDR 1.8M++. As the hotel was still in its soft-launch phase, there was only limited availability of room types and I wasn't offered any upgrade on check-in. Given my meeting schedule and since I was traveling alone I didn't expect to need too large a room, so this wasn't a big deal. 

Check-in was handled smoothly. I had also been corresponding with the guest relations team regarding a kueh lapis delivery which I was expecting while staying at the hotel, and they had alerted the front desk so that final arrangements could be made on check-in. This eventually went without a hitch (I wasn't able to be at the hotel during the delivery hours, and hotel staff sent the lapis up to my room). 

Room

My room (on the 60th floor) was up to the usual Westin standard - heavenly bed, full bath and shower, good sized desk for doing a bit of work, etc. All in mint condition since the property is new (though the hot water flow/temperature was a little inconsistent; par for the course in most of Indonesia). Amenities were all standard Westin product (e.g. leaf-shaped bars of soap).

I appreciated the view of the city (not that Jakarta's that much to look at!)

One nice (non-standard) touch was the mini walk-in wardrobe, which helped me to keep my clothes in one spot (instead of strewn around the room.) Couldn't figure out how to make this photo appear upright - sorry!

Dining

Breakfast is at the Seasonal Tastes restaurant and is reasonably good quality for Jakarta - there's a wide selection of local and international food and fresh fruit, all of decent (though not exceptional) quality. The one part of the breakfast offering which was special to me was the cold plate yoghurt/ice-cream and granola mix (think Cold Stone with a slightly healthier choice of ingredients). Unfortunately in Jakarta (as in much of Southeast Asia) the humidity means the plate constantly has a layer of ice on it which affects the quality of the outcome, and it was hard for the outcome to be served really cold as well - which meant this was just an interesting idea, not exceptionally well executed. 

I didn't eat anything else at the hotel.

Location

The Westin isn't at the heart of town, but neither is it so far out as to be remote. I found its location suitable for me (many of my meetings were in the SCBD/Gandaria area, which was easier to get to from the Westin than a more central location. The main drawback is that because it is still relatively new, taxi/uber drivers are often not sure where it is. I found it helpful to direct them to Gama Tower, via Jalan Epicentrum. The view from the lobby was pretty good at night (my hastily taken photo doesn't do it justice).

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Facilities

One drawback is that there aren't many facilities at the Westin (perhaps this will have changed by now, but it was the case during my stay). I used the gym once - it was equipped with many elliptical trainers and treadmills but not much else. 

Also, the gym door had no real access control. This is the view from inside the gym: there was a button (presumably to unlock the door) on the inside, but the door was not actually locked at any time when I was there.t

Overall

The Westin Jakarta is a fairly standard Westin hotel, and a reasonably good example of the brand (when new). I enjoyed my stay and would choose it again if the price were right - i.e. if The Hermitage was much more expensive. Your mileage may vary depending on the location and purpose of trip - for my purposes it was perfect this time, but (at least at the time I stayed there) it lacked the charm, luxury or full service offered at some other Jakarta properties.