Chinook, Aldridge would probably play 4-5 mpg less in the regular season than he's accustomed to with the Spurs. Splitter is a better overall defender, but it's not as if he's a great defensive rebounder/rim protector either.
In terms of being a long term building block, he sure as beats Splitter and two middling prospects. His game should age well and a Parker/Aldridge/Leonard/Green core, with cap space to add to it, would keep the Spurs more than compe ive post Duncan/Ginobili. Besides, it's not as if they have any hope of doing better than him.
elemento, given that Allen has essentially mandated that the Trail Blazers be Bucks West, this is a good trade for them. The Hawks would probably be the tougher sell; their level of interest would depend on if they were high on any of Freeland, Claver (both had awful rookie seasons, but have long been considered solid prospects) or whichever of the Spurs assets they came away with. But if it required giving them whichever was leftover among the 1st/Bertans/Jean-Charles, I'd do it in a second.