The offers are almost always more generous than what you would get if you asked them to review your play at the end of the trip, unless you played significantly more than you usually do. And if you have a bad trip and lose your bankroll quickly, then it will be doubly bad because there won't be enough play for them to comp you against and you could walk away with no comps.

Of course there are some times where the FHR rates are low enough that it might be advantageous even if you don't get any comps. One night at Delano for $70, including $100 credit and $60 breakfast = net -$90. A casino marketing offer for a low roller might be a comp night plus $50 credit = net -$50. So there's a $40 advantage to FHR on a one night stay. Every night beyond that reduces the advantage by $10 ($70/night-$60 breakfast). (Assuming in all cases that you are using up all of the credits and in an efficient manner - I have had plenty of stays where I buy stuff I wouldn't spend "real" money on but I don't want the credits to go to waste - like a $10 coffee and $5 apple at the Waldorf, as I mentioned above. And I'm ignoring taxes (13.35%) and resort fees, which have a fairly small effect.)

So I think there's a very small window where you could end up ahead booking with FHR and getting comps on the back end. But your best case here is to come out ahead in a very small way, and thus I don't think it's a good bet unless it makes sense even if you get no comps, like in the Delano example.

Of course if you're a high roller then the rules are different, but in that case the offers you get (or your host) will include enough F&B credit to make up for what you would have gotten from FHR.