It stinks to want Morse gone, because he's such a great personality. But it's about winning. I think re-signing LaRoche seals the deal in making the Nats a pre-season favorite, while keeping Morse would be a compromise in an offseason that shouldn't be about compromises.
Rafael Palmeiro is a guy who I think was similar to LaRoche - good fielder and a very relaxed looking left handed swing. He was durable and was good into his late 30's. But who knows how much the PEDs helped him do that.
Most of the guys listed as the closet comps for LaRoche by Baseball-Reference were done as productive, full-time starters by 32/33 years old. Which is exactly how old LaRoche is.
http://www.baseball-reference.com/players/l/larocad01.shtml