So I compared Chandler's 6th season as a 24 year-old player and McGee's current season as a 24 year-old. Here's how the stats look:
Chandler shot for a way higher FG% than McGee, though McGee takes more shots per game. Also, Chandler is a terrible FT shooter at 52%, but McGee is just plain atrocious at 42%.
Despite McGee being the superior athlete, Chandler was more active on the boards, both offensively and defensively and at 24, Chandler averaged 12.4 rebounds/game. 9.3 for McGee--not bad, but for a guy with his skill set, it could be higher.
Neither big men would be confused for Marc Gasol-like playmakers, but at least Chandler can brag how he averaged 0.9assists/game. McGee does have an advantage in the steals department at 1.0/game as his long reach and wingspan must be a nightmare to deal with.
McGee is averaging 3.2 blocks/game compared to the 1.8 Chandler mustered as a 24 year-old. The turnover battle is a wash.
Points per game is where McGee gets the final edge over a younger Chandler at 11.4 vs 9.5.
So McGee is progressing better than Chandler did when he was 24 years-old. Chandler who at that time was playing with Chris Paul, might have played his best overall season then. McGee can not only match Chandler's production, but surpass and is miles away a better athlete than Chandler. Chandler ended up having to battle chronic back pain for the remainder of his NBA career. Literally, the sky is the limit for McGee (have you seen him dunk? Should've won a dunk contest already).
However, McGee, at times, has shown to be an idiot on the floor as he takes bad shots, is sloppy with the ball, plays bad defense, and just makes overall bad decisions on the court. Again, his defensive numbers are a product of his athleticism. So McGee is just another project big man for any other NBA team that is not the Wizards. The Sacramento Kings are loaded with players just like McGee. Not as athletically gifted though.
The final verdict: If I'm an NBA club that needs to win now, then Tyson Chandler is the clear choice. He's not flashy like McGee, but at least he knows how to play with an elite point guard (i.e. Chris Paul, Jason Kidd), doesn't exceed his talent like McGee who sometimes wants to play point guard (he shouldn't, by the way) and what he lacks in blocked shots, he makes up in knowing how to play defense.