No question Feliz is in a serious groove right now. If you own him, shop him. The hype machine is on tilt after tonight, and his value may never be higher than it is right now.
Feliz is a .268 lifetime minor league hitter, and was at .242 in 608 big league AB coming into this year. No question that he has power, definite 25-30 HR potential. But he won't be a .300 hitter, won't deliver speed, and may not deliver all that many runs with what's behind him in the Giants lineup.
Plus side is that he'll have multi-position eligiblity. Definitely 1B-3B and maybe even 2B. But with Durham's return, he also loses a start or two weekly.
If you can find an eager buyer hurting at 3B (try Glaus or Koskie owners with the DL looming for both), he's great trade bait.