I've been to Rios four times in the last six months, and my advice would be to go for the facilities (I genuinely rate their Jacuzzis for whenever I'm feeling stressed out, it feels like getting a fairly decent back massage) but the behaviour of some of the men is ridiculous, I've seen some spend the entire night going around from steam room to sauna to the play rooms over and over again and it looks not only ridiculous but exhausting. I'm not saying I haven't attempted flirting, and some of the women are more than happy to chat, but many make it clear that they're just there to relax and don't want to talk to anyone they don't know, but some of the guys are persistent in a way which clearly pisses them off. Its not always like that, but it is a little too often, and given my age and body size it's extremely likely I'd pull there, so I tend to stick to weekend afternoons now where it's rare that many women will be present but it also means I get the jacuzzi to myself!