It depends on where and how you stay. I was Diamond with Hilton for years and only saw benefits in increased points on the vast majority of my stays. I was always on the road mainly in boring Hampton Inns and other hotels in that range so there isn't really much to get. I did get a few amazing upgrades staying in higher end properties, though.

I decided to bounce around and see what was going on out in the other chains and am about to hit Platinum with Marriott. So far, no real difference.

I'm going to just pick whatever has the hotels I like.