Just a bit of my experience --

I travel all year, and rack-up a Quintillion points with Marriott, Hilton, et. al., and now want to use a few points to stay at a Marriott property.

Capacity controls. "I'm sorry, but there are no award rooms available." I am not in a black-out period, but still no rooms at the inn. Plenty of rooms if you want to pay for one.

This does not sit well with me.

I think my vote for best hotel program will go to Starwood this year, for having no blackout periods and no capacity controls. I also might reconsider and cash-in my hotel points for miles.