I have been a member of Marriott Rewards since 1996 and have enjoyed many vacations using my rewards points. I even got the credit card which help boost my points. I think it is a great program and have encouraged many of my friends and family to join!
I am hooked on Marriott Rewards too, as you can tell. My rationale is that I am loyal to Marriott and they are loyal to me as well. I feel at home speaking with the associates and the folks at the 800 numbers, the hotels are always welcoming and the company is one that I greatly admire.
Marriott and Marriott Rewards are, for me at least, one of the best things about travel and leisure, now that I am (mostly) retired.