A slightly different perspective but limited
Avid,
I can't answer you specifically on what you need as I'm not such a high level hotel elite. I am however enrolled in the HH club as a non elite and the MR club as a Silver very close to Gold right now. It wouldn't take much after that for me to reach Plat.
I just spent a great deal of time reading a thread in Milesbuzz about which program is the best. It would seem that the SPG program is the best for upgrading a room. Marriott is best for service. I have a HH account mainly because I had to stay there for business and I wanted the points and use it as a back up.
I'll tell you why I use MR. First I am a suite junky so I may look at joining the SPG program for just that reason. However I do a lot of traveling to Russia and prefer to stay at the Marriotts there especially the Ren. in St. Petersburg which just opened 2 years ago. Also I am hooked on renting those damn villas on a nightly basis when I can afford it. They are so comfortable and I am able to bring the family along on business and not feel guilty when I have to work and they are 'stuck at the hotel'. While I feel timeshares are too expensive I can sometimes get great deals at the villas. Finally the Residence Inns are also nice and I love the newer ones with the 2 bedrooms that act like a mini villa for the same reasons above.
Couple together my leisure patterns and I guess I need Marriott as I like their product lineup (others gasping for sure).
I'll be happy to help tell you anything you want about Marriotts as I have stayed at the villas, RI's, Ren, JW and full Marriotts as well as CY. The current 7 page thread on pet peeves will be interesting reading as well.
Best of luck in choosing!