Antoine Walker was in fact a very good player. He is one of the best offensive rebounders I have ever seen, and early in his career had the same type of quickness and hands around the basket that make Powe so effective...except with a few extra inches, and much better overall ball-skills.
The problem is he both fell in love with the 3 pointer, and he lost a bit of his quickness, so instead of being able to slip the ball past shot blockers, they were able to catch up with him.
With that said, the more I see of this team, the more I think if Antoine is bought out, and is in good shape, they absolutely should consider bringing him in (if there aren't significantly better options). His versatility to be able to rebound, play team defense (he was always an underrated defender...he just couldn't handle extremely athletic big guys like Martin), and stretch the defense with his perimeter game (both shooting and passing) could really help this team off the bench, and down the stretch of games, when teams sagging off Perkins and Rondo.