I have been Marriott Platinum now going on 3 years. I started my business travel in Marriotts and never looked back.

I really like the Rewards program. I have never had trouble booking rewards rooms:
[*] Two days noticed in November for 5-day stay at their Peurto Vallarta resort into a Suite. One of the days was 'unavailable' but the agent seemed to be able to override that.[*] Reasonable values to get the rooms. 50,000 got me a suite at the Courtyard Paris last week for 3 days.[*] Quick to compile...at full-service Marriotts, the fact you get 10-points per dollar, including meals, plus the bonus...I can't spend my points quick enough. Now with the inclusion of all Marriott properties into the status bonus, life is only getting better.[*] I have stayed at hotels all over the US and Canada. Not once have I ever not received my upgrade to the Conceirge level. Once, I checked in and only had 3rd floor (20 story hotel). I called down and asked what was up. My number wasn't in the account. I just asked them to add it and was ready to leave it at that. I didn't ask for the upgrade now (I was only there for 3 days). 10 minutes later, the bellhop arrived with a new key to their suite on the top floor. He even helped me re-pack some of the stuff I have already taken out.

I have a lot more positive notes for them, but my flight leaves in 30 minutes