Just checked out after a 2 night stay.
Well the good:
As a platinum was upgraded to a suite on the 21st floor, it seems there are 3 suites per floor, all on the corners of the building with the 4th corner resereved for the service area.The room was enormous size consisting of 2 rooms with a very large standard living room area and TV, work desk, minibar etc. and half bath.Very comfortable indeed,aside from smaller flat screen TV 20".
The bedroom consisted of another small desk and TV ontop of amoir with storage area and a closet with plenty of racks, another storage area for luggage, well planned for those with alot of stuff.
The bathroom was very opulant and large,seperate bath and shower stall and some very nice toiletries (probably best of all the spg properties in BKK) with very good lighting.
The lounge located on the 26th floor was the biggest I've come across here in Thailand with 2 rooms one with a bar and the other where breakfast and canapes were served as well as afternoon tea.Also you will find meeting rooms on this floor and 3 computers and lounge attendant service desk.A very comfortable place to hang out in,where they also have 2 plasma TV's.
The breakfast was full american buffet with a cook waiting to prepare eggs. Decent selction for breakfast in a lounge, but not the selection one would find in a 5* hotel coffee shop buffet downstairs.
After 6PM had a good selection of drinks both hard and soft.

The bad:
First the bed was way too hard! No sweet sleeper here.Pillows that were very firm. By far the most uncomfortable of all the SPG properties in Thailand.
The lounge although very large had very weak assortment of canapes at night 6pm-8pm(cheese but no crackers, cold canapes that were meant to be served hot, and mislabeled small sandwhiches overdone with mayo).
The staff. Well,they say that one returns to a particular hotel because of the staff and how very at home they make you feel. I guess this decieding factor makes me never to return to the Plaza Athnee.All very stiff and ungiving of there time.As from the time I checked in, till when I left, I got the feeling they were all doing me a favor to stay. Aside from the 1 lounge supervisor who was a very informative and helpful aide I cannot say too much for this poorly,complacent trained staff.