If you're not doing many stays at Marriott properties, then no status is worth much. And the Marriott Visa card isn't much good except for use at Marriott.

If you are a Silver, and you do stay at a Marriott, you get a 20% bonus on your points. (Golds get 25%, and plats get 30%, so there's not a whole lot of difference).

For spending your points on awards, you have the same availability as everyone else, so no particular benefit there.

If you do get the Marriott card, you will get a cert good for a free night, so that's a nice little bennie.