I never experienced this first version of Babylon, but I guess it must been what gave Babylon the reputation of the "sauna-to-go" in Bangkok. As for me, in my last 6 years of traveling to Bangkok, I never enjoyed Babylon that much. The facilities were great but It was getting overrun by farangs well into their retirement years, and the number of young locals was decreasing on each visit. Even in a smaller saunas like Mania in Silom, albeit more run-down, I could always find 1-2 young Thais to have fun with. The only occasions I liked Babylon was during their Songran's foam parties, but that was mostly because of more young people being in town.
Never went to Chakran. Heard their facilities are good, but that the crowd lacks young local twinks.
I would say my favorite sauna in Bangkok is R3 in Rama IX. I think it might have a new name name now.
I used to go there during their O-party nights. The place would get packed. It was 90-95% Thai and Chinese, majority of them young and slim.
Yes, a good chunk of them were sticky rice, but just because of the large crowd, I was always able to find a few guys that enjoyed my company and you could still off one of their models/performers after their sex show, even if you didn't find anyone interested in you. So, it was almost guaranteed fun for the night. They also used to have foam parties for Songran and it would get completely jam packed, even more than at Babylon.
I know there is another sauna in Bangkok that does some sort of masked party night. Went once, but don't remember then name.
Anyway, as long as masks will be required inside, saunas will lose much of their appeal. I tried a few last year in Europe and the Sates where you had to go around with a mask on. It takes away so much from the cruising experience.