[IrishHand]

I totally disagree. Here's one way to look at it from Milwaukee's position, assuming they let Payton walk:

Give up:
Ray Allen - max contract, marginal defense, didn't get along with Karl, team underachieved at least three years in a row under Allen's suspect "leadership" (I realize Karl takes some of the blame for this, but Karl did more with less in Seattle and at some point the players take a chunk of the rap). Really - he was paid top dollar and wasn't giving superstar production. If you go down the list of max contract guys you'd want to build a team around, he's not in my top 10 (O'Neal, Bryant, Duncan, Garnett, McGrady, Kidd, Webber, Nowitski, Pierce and Marion). Certainly, I'm not saying he's not a valuable player - I think Seattle comes out a better team after this deal for a number of reasons - but thus far, he hasn't demonstrated that he's the kind of player to lead his team to the promised land.
Conditional pick - as I understand it, this is either a crap 1st rounder or 2 2nd round picks in this year's draft. Probably not a huge factor, especially since I'm pretty sure that if the Bucks make the playoffs, it's two 2nd round picks.

Acquire:
Payton for the rest of the season - one-for-one, a clear improvement over Allen the rest of the way this year, dominant defender to go along with same level of offensive skills as Allen, with a straight-up Allen-for-Payton trade, I'd have moved the Bucks from the 6-8th place in the East to 3-4th.
About $10M per year against the cap and the balance sheet after this season (net of Allen plus Ollie minus Mason) - makes the team more attractive to potential buyers. It also affords them the possibility of being a player in the free agent market the following summer when a bunch of their veteran's contract's expire (I believe the only people under contract for 2004/5 are Thomas, D. Mason, Cassell, Gadzuric and Redd - a fine core).
Desmond Mason - a very valuable player, mostly 'cause he's still under the rookie wage scale for another year. Very good defender, insanely athletic - sort of a poor man's Shawn Marion. Also, an excellent fit with Karl, who loves athletic defenders and was sorely lacking them in Milwaukee.

Overall - Bucks much better this year. If Payton leaves, they've gained cap flexibility and a cheap, young player who's a far better defender than Allen, although not anywhere near the offensive force. However, Desmond was averaging 14 and 7 off the Sonics bench, so he could put up decent numbers in a starting role (16 and 8 seems reasonable). Of course, if the Bucks resign Payton for 4-5 years, then I think they come out of this deal smelling like roses.