I agree that for mid-range players it seems like totally free hotel room offers in Vegas are less common than they once were, but it does seem like there is more of a discount-across-the-board methodology.

So for example a few years back I might have gotten an offer for 1 free night at Mandalay, and any additional nights would be at retail rate. Now, the offer says there is the possibility of 1 free night, but usually there are only a handful of eligible days on the calendar. But if I want to book 3 nights, all 3 are usually significantly discounted from the retail rates, so for a 3-night stay I think I probably still come out ahead vs. the old way of doing things. (It is odd, though, that even at cheap properties like Excalibur, free nights are still extremely rare, even though my account often shows $20ish/night rates at the lower-end properties. You would think at that point it would be worth the customer goodwill to just go ahead and offer "free" nights, especially since they still take in a solid amount of money with the resort fee.)

Not sure if it is the case for slot players, but for table game players, Mlife has also gone back to the old "ask what they can do for comps at check-out" approach where they will evaluate your play and take some amount off your bill, vs. the "Express Comps" approach they had used for a while where you had a running account with a $ amount in it. In my personal experience the "ask at check-out" approach has always yielded a much higher $ value than the Express Comps system did (perhaps in part because some people don't know to ask for it and so it costs the casino less).