In the for-what-it's-worth category, I'm a low-end Silver. I get 15 nights from my MR visa and while I generate a few rewards points by putting the rooms of some of my traveling companions on my card, I average maybe 10-12 nights a year, so I'm not even close to Gold. However, I have found two major benefits of being Silver:
1) As much as people around here grouse about the lack of service and respect for loyal customers, I have found the people on the elite reservation line to be considerably more friendly and helpful than those on the standard Marriott reservations line. It's the little things, but they add up to a better experience.
2) Usually when I'm checking into a Marriott I ask if there's any possibility of being upgraded to the CL. I wouldn't even think of trying this if I wasn't Silver. Surprisingly, even though my night count is low (and I'm sure they know that 15 of the nights they see are from the CC I'm paying with), I have almost always been given the free upgrade, or at least access the lounge. I know they the staff is under no obligation to do so, and I would never fight them if they said no, but I've found that they don't, so I get the benefits of the CL.

...I'm actually going to be staying 10 nights in about a 2 month span from March to May, and paying for 16 nights (one of those group trips), so I'm thinking about trying to get a challenge to see how the Gold folks live, but I know the odds are very, very slim of them granting that. If they don't, that's fine. I think Silver is pretty nice as it is.