In my experience, and I am a Platinum with Hyatt, I've only once, in 5 years, been able to redeem ANY hotel rewards with Hyatt, and I try between 2-3 times a year.

How's that for horrible luck, and we're not just talking about lux resorts (6 free nights/6 free nights in a Hyatt suite), I'm also referring to one to two day stays with this hotel chain (1/2 free weekend night(s))

Hilton, where I am a Diamond member is by far the easiest for me.