I have played here 4 times over the last 2 months on random Fri/Sat nights, and action is decent until about 2am when the recreational crowds begin to thin out and the broken tables begin to consolidate. It is then very rare to see people drinking after 2am when it becomes very clear that it's mostly the socially awkward local regulars. They're mostly younger (20s + early 30s) and relatively annoying to be around because when they do decide to talk all they talk about is poker, or how lucky you got winning a particular pot against them. I've seen the same 15-20 or so locals spread across three 1/3 tables at the end of the night (5am) every single time I've gone.
I had wrongly assumed that the local players would be cool and interesting, this being DC and all, but I was way wrong. This core clientele is despicable! And they're terrible tippers - the regulars tip only $1 regardless of pot size, sometimes $0 if the pot is smallish. I feel bad for the dealers who got stuck with this lousy customer base.
Don't go here hoping to have any fun socially. In terms of fun, this room is definitely not the place - nobody drinks! If you *must* play here, Just hit and run, because if you stay too long I promise you'll start to get annoyed by the local young regulars who have pretty much ruined this room already with their collusion and unfriendly gang-mentality. On my last trip, one of the young regulars threatened to physically harm me after I verbally stood up for myself after he taunted me, and the poker room manager did absolutely nothing. In Vegas that dude would have gotten a stern warning at the very least.
In addition to a crappy player atmosphere, the overall lighting is uncomfortably warehouse-like: the worst kind of efficient LED fluorescence that feels like you're in a weird Costco casino.
Needless to say, by the 4th trip to MGM I was completely over it. Not to mention basic beer prices are actually *raised* on the weekends (from $6 to $7). That's not fun, either!
Pros: nice chairs, clean felts, cupholders, free coffee
Cons: tables are cramped, the locals are unbearable