On my first stay here I applied a TSU, and they upgraded me to the next level of suite (which is slightly bigger, though not that different, but still appreciated. The standard suites are true suites and quite large)
On my 2nd stay (noted above) the only suite was a smoking room so they did not automatically upgrade me since my preferences said non-smoking, but they upgraded me when I asked. I've since changed that preference in my profile.
I'm not sure what the complaints are about not upgrading people when they are supposed to. I haven't had a problem so far.
As far as there being prostitutes... so what? We are all adults right? Just say "no thanks" and move on. Personally I'm not sure why anyone would pay for it in BKK but I don't have a problem with it so long as they aren't being aggressive or harassing people. If they are, just report it to security.
This is my go-to Hyatt in BKK. The regency seems a lot less nice for not much less money, and the PH seems nicer, but not enough of a difference to justify the huge price jump. This hotel seems to be in the sweet spot for value.
Also, great restaurant breakfast (free for globalists -- this is over and above since they could limit the benefit to the lounge breakfast) and the fruit bowl, replenished daily, in the suites is a nice touch.