He's a better-than-average player when motivated. And he could be motivated if he were in a different situation. He's a good rebounder for his position (which fits a need) and because he's so good at drawing contact and getting to the free throw line, he can be a CONSISTENT scorer. At 27, he's 8 years younger than Barry.
Bottom Line: Maggette is potentially more productive than Barry, Finley, Udrih, and even Bonner. If the Spurs need to give up one, two, or even three of those players to get the deal done, they should make it happen.
Keep in mind, the Spurs still would have the expiring contract of Williams to fill the holes created by the multi-player trade if necesary.