that sa tough one for me, but I'd probably go with Hyde, I like his pedigree more than the ACC roots of Williams, and, like Monkey mentioned, I think he's currently in a better situation.
I would not be shocked if Williams ends up better down the road, but it'd depend on coaching changes, philosophies and and all that. Tough call there, as that'd require some pretty strong crystal balls to see.
for this season i would say williams, just because the giants have had best success in the past when they have had 2 RBs being successful...
The 49ers are going to run gore crazy until he cant run no more... for the future i would pick hyde only because the 49ers are more of a 1 RB system team than the giants...