Watdee.
That there is no www says really nothing here. Plus that in many cases (I mainly use those m2m msg shops) a former www -payable, so avoidable/unliked by Thai- is replaced by the various new forms of free IT; tweet, insta, and that LINE that is so immense populair here.
Some of these you list have discriminatory pricing for older people (yes, they do ask for ID-which you have to have on you as such anywhere here and is for Thai quite common to asked for) and some also for farang (I think V-club / chakran). But even then the higher price is low compared to current EUR prices. Some (Mania) is also mostly known as ´only for sticky rice´, but I really have no idea how strict that is or just a casual impression.
R3 was raided by police some time ago and closed for a while- drugs found.
Faroth (thats how they say it) has 2 outlets-both incredibly dirty and unkempt-think even of broken glass lying around-one in Sapan Kwai and one along RamKamHaeng (TH biggest uni). Report: quite a few guests did not even bother to undress there.
All in all-and I am quite a bit older as he- I do agree with Chris that sauna´s here in BKK are hardly worth the effort to go there-as a very broad general rule. Which I found was quite different in the provinces (Ch.Mai-H.Yai). Remarkably around/near most of the sauna are also these m2m male for male msg shops that can deliver garanteed service if so wished-or if not found in the sauna. Yes, Thai can be quite keen businessminded.
What will take over the function of now sadly closed Babylon remains to be seen-no clear winner yet noted. But inevitably some of those bright bisnismen must notice this current hole.