As far as the hoops you jump through to get access, I really enjoyed it. A speakeasy in Vegas is rare to this degree and as long as Laundry Room has been around I feel like word is not out yet. The text and reservation gimmick was very cool and I respect them for that.
Once inside they have about 3 tables a bar set for 10 and a few more extra seats lining the outer walls. I would say you could get 25 in there without a problem. The main problem with that many people would be the bartender's ridiculously slow process of taking orders and making drinks. We got there about 10:30 and didn't receive our first drink until 11:15. We only saw one other table receive drinks in the interim. Out of our total party of 4 I would say 2 thoroughly enjoyed the concoctions (off menu order specialties by the bartender), one enjoyed his drink but didn't say it was best old fashioned ever but solid, and one hated the drink as it had too much ratio of sour mix to whiskey. For $15 the price doesn't match the time and quality taken for the drinks. But the ambiance was very nice for an intimate evening for cocktails. You get free entry into Commonwealth with your reservation to Laundry Room so that by itself is a solid reason to grab a drink here before heading to the roof of the main bar. I probably won't be back because I like other cocktail bars in the area better, but that doesn't mean I wouldn't recommend the experience.