+1 on consistency versus SPG. I began chasing status with SPG several years ago when I stayed in a beautiful Four Points hotel near a client I was working at for 4 weeks. Then I stayed at other 4P properties and found them to be holes. Ditto some Sheratons. Yes, SPG has some beautiful vacation hotels in their portfolio, and their Amex has a good earn/burn ratio, but it's tough when you're on the road and you never know what quality of hotel you're going to find when you check in.
It's worth mentioning that HH properties are pretty consistent, too. And at the low end, HI and HGI are consistently better than FI and CY.