I've been as a single guy a few times - got seriously laid one time (even went home with her too), and got to fuck someone in the dungeon another time - several guys were taking turns - I think it was the owner? One other time, started chatting with a super cute kiwi girl on the second floor but chickened out. Also, went with a date which was way better, but she's not bi, so we didn't indulge much.
Another time, no luck but got to watch a very hot couple doing some serious exhibition sex on the 2nd floor.
However, I've also gone once or twice where I feel pretty much alone as couples clinch together and rooms are empty.
I'll hit it up again this week and write a review if anything happens. It's $60 - I spend more in data a month. Might as well try my luck at Oasis!
UPDATE
So I went last night. Got in about 10:30 - big line up at the door since the place was packed. It was the first Tuesday of the month, so a special night for couples seeking multiple men. At the door, there were two hot ladies, so I figured it would be a good night.
Inside, there were lots of couples and single ladies - about a match to the guys, but maybe a few extra fellows around. All shapes and sizes. I hung out beside the pool and chilled on a bench and took in some live sex in the pool - in particular, a guy who was banging his partner for at least 20 minutes solid as she came repeatedly. Verrry impressive! I flirted a bit with a couple in the pool, and then moved on to the upper floors. The dungeon had a game of Truth or Dare going in with a mix of men and women. Dares where things like "Fuck her as hard as you can" or "Fake an orgasm in front of everyone". It was fun to watch and I would have joined in, but instead headed to the sauna. I walked in and there was a cute woman inside with a glass of wine. We talked for a long time having a whole bunch in common. Her hubby was in the hot tub, so she gave me a high-five and left, saying "see you in the pool". Well, I took that as an invitation - but never saw her again. Perhaps she and hubby went to the top floor (men can't go up without a female or couple).
Being tired and too hot, I took one last stroll around and packed up to leave.
Overall, a great night and lots of smiling people. I think if I'd have had more gumption, I'd have found my sauna friend and joined in for a MMF since she was hinting at it in a big way.
The key to Oasis is to head in with no expectations, no preconceived ideas. If you ask, according to etiquette, you might get laid or join in on some group action. Otherwise, it's a chill place to go, get naked and take a break from the rat race.