I've been to a bath house several times in recent years. It's been a great experience overall, but can be extremely hit or miss.
I'm overweight, but was otherwise young and cute enough, so I attracted mostly older men, which was fine with me. I was chased by a lot of Asians too. Every time was different. One time, nobody was very interested in me, so I ended up jerking off while watching two guys make out.
The key, as was said, is to not have expectations. You're going there to get off. But how entirely depends on who's there when you go.