Yes, the Hyatt Regency Sukhumvit is a solid property. Most of the service is very good, but at some points there seems to be a lack of staff. The Privé rate with a 3for2 offer is a very good deal. They are less generous with upgrades at this property.
If you want to have in-room dining, I recommend the “by Khao” menu. It’s really good. You can order everything on the “by Khao” menu, not only what’s on the in-room dining menu. The “by Khao” is available from 6pm to 10pm. Can’t recommend the Western food on the menu.
There are big windows in the bathroom, even where the toilet is. There are electric roller blinds, but you can close all windows or none of it only.
If you get a room on a lower floor, it can get quite noisy (traffic, BTS).