While I think the Hyatt program seems to have some very nice features. My two big gripes are there just aren't enough Hyatt's around where I need/want to travel and when there are Hyatts, they tend to be more expensive than the FS Marriotts close by.

Also, I'm not sure that I would completely agree that staying at Hyatts will, in general, net someone more free nights. Yes, they may currently have a better promo, but I'm not sure I would count on them always having a better promo. And if I'm traveling where there just isn't a Hyatt (and even in the US their coverage isn't close to Marriotts), I can't earn free nights there (whether or not they have a great promo.)

I do agree, though, that anyone who is currently or getting ready to travel much, should definitely look at the strengths/weaknesses of all the programs and compare those with what you want to get out of a stay program.