So, we stayed at the Madrid Marriott Auditorium Hotel last year and really enjoyed it. They bent over backwards for us. I don't know how many Platinum (at the time there was no Titanium) Americans they get, but they gave us a very large suite, and we didn't even ask. Even comped my kids breakfasts (they were in a regular room). My wife and I (guest + 1 only) availed ourselves to the lounge, they did seem strict on that point, and I didn't want to push things. Didn't make much sense to me, I figured lounge would be cheaper for them than the restaurant, but, whatever.

Downside...it's not really near anything, including the airport (well, let me amend that, it is near the airport, but the airport is so damn big, that it takes forever to get to the hotel).

We had to take a bus ride (albeit not very long) to the nearest Metro station. Once we were there, of course, we were able to go anywhere in Madrid, which we, of course, did. On the way back, you just have to make absolutely sure you get on the right bus. It stops right at the hotel.

If you're on a budget, it is much less expensive (at least points-wise) than staying in downtown Madrid.