Some numbers to compare:
Chris Bosh
6'11", 235 lbs.
PER at PF: 19.4.
Opponent PER at PF: 15.6 (net +3.80)
Defensive Reb Rtng/Total Reb Rtng: 20.6/13.5
Thaddeus Young
6'8", 220 lbs.
PER at PF: 19.5
Opponent PER at PF: 18.1 (net +1.4)
Defensive Reb Rtng/Total Reb Rtng: 12.0/10.3
Ersan Ilyasova
6'10", 235 lbs.
PER at PF: 20.3
Opponent PER at PF: 18.2 (net +2.1)
Defensive Reb Rtng/Total Reb Rtng: 22.8/17.6
Amir Johnson
6'9", 210 lbs.
PER at PF: 14.8
Opponent PER at PF: 13.6 (net +1.2)
Defensive Reb Rtng/Total Reb Rtng: 19.3/15.4
I think the PF matchups are very close. Better collective PERs and PER differentials for Chicago, better rebounding for Detroit.
When Thad Young comes in for Philadelpha, his team scores 8.2 points per 100 possessions better than compared to when he is out.
When Ilyasova comes in for Milwaukee, his team score .08 points better than when he is off the court.
I think that Ilyasova's skill set is a lot sexier than Thad Young's, he's got those gaudy 3pt numbers. But the problem is that Ilyasova only did that for one half of an abridged season. There were five halfs of a season before that when his production was as inconsistent as you could ask.
I know, because I argued 2 years ago using his gaudy per36 numbers and tantalizing games here and there that he could be a 15 and 8 guy shooting 38% from range, and followed him like a lot puppy the entire 2010-2011 season, just to see the guy fall flat on his keyster.
Now maybe he does get it, and maybe that all works out
But if you're talking about regular season wins, I think the evidence is there that Young's 2 years of consistent play involving a consistent role, playoff and big game experience, and consistent minutes are a better piece than Ilyasova's. Just last season, why Ily was crazy-town-banana-pants from deep, Young still managed to make a bigger difference helping his team get wins than Ilyasova did.