I'm mainly interested in experiences in the USA.
I'll be spending about 30-40 nights in US hotels for business travel each year. That's not enough to make the top tier or demand celebrity treatment. But I'm hoping it's enough to occasionally get better rooms, late checkouts without a negotiating session, and access to decent lounges. Since most of my trips are to NYC, LA, and other major cities with high prices, I build up points very quickly. My company lets me keep the points, but does not authorize stays at higher end brands like Ritz or Conrads.
I tend to use my redemptions for vacations at the high end brands. It annoys me that I don't get any of my Platinum benefits at these hotels and am often paying resort fees. This is one of the reasons I'm considering switching to Hilton.