I'd choose Smith over Sully
I'd choose Smith over Asik
I'd choose Smith over Hump (tougher choice, but I would)
Even at his worst, Smith's production has beenonpar with someone like Sully. At the VERY least he's a 16/7/3/1/1 guy. At best he's a 18/9/1.5/2 guy.
Like Rondo, Smith is a guy who can exclude any given night with a 30 point, 15 rebound, 8 assist game. Sully might never record those type of numbers in his career.
Also Smith's contract if he DID fit in, could actually be an asset. If he ever cane even close to realising his potential he'd be an instant All-Star and a max contract guy. Having him locked In for < 14m over the next 4 years could prove a bargain. Is not like he's on a Amare / Gasol / Johnson like $20M a year deal. He's only costing us 30% more than Wallace over the first three years and he's about 10x better a player. The last year doesn't matter because he'd be an expiring contract anyway, abd hence a good trade asset. If you are losing Wallace in the proves you'd be nuts not to do it.
No doubt J-Smoove is highly talented, more talented than Sully.
But I'm under the impression he's like DMC of last year, JR Smith...maligned. Maybe a little bit of Rudy Gay of last yearand Jeff Green, coasting through games. Again the question is: at what point do you stop talking about potential.
J-Smoove can win games single handedly, putting up, like you said, monster numbers. But I've read he can also single handedly shoot you out of games.
Sully, however, will bring it every night. Grabbing a butt ton of rebounds, scoring efficiently, hitting 3's now. He will hustle. He will make "winning plays".
However, I do have a feeling there's a greater chance J-Smoove makes more of his potential than Jeff Green. Smith has better handles for one and doesn't rely on his scoring so much.
But there's still significant risk, since you're potentially building yourself a mediocrity treadmill with Smith's cap hit. I'm definitely not going to give up Sully for Smith, that's for sure.
You're right, though. People are too down on Smith.
A change of scenery could help.
Not having watched much of Detroit basketball, I suspect having adequate defenders instead of a defensive liability in Greg Monroe at the 4, J-Smoove might actually play the 3 pretty well (I've read he overhelps on D, perhaps this habit might change). On offense we'd have a better fit, for sure, with Sully and Olynyk being much more of outside threats.
And I think shedding Wallace with 2 or less picks while getting J-Smoove back is definitely something I think Ainge should consider. This has been on my mind, bugging me for the past couple days.
The upside is incredibly alluring, especially considering that he's going to come at a discount. Now you've got me daydreaming about Smith doing well on this roster.
The obligatory Rondo-Smith connection...
Smith/Sully/KO with the incredible size and inside-out game...
Smith/Hump/Sully with all the rebounding...
Of course, the defense with AB/Rondo and Smith would be incredible...
Throw in a semi-legit center like Asik, and you have quite a bit of potential...But on the flip side...
Josh Smith launching long twos 
...
Winning us just enough games, tricking Ainge into committing more salary and dumping young players for role players, only for eternal first round exits...
Josh Smith is tormenting us, one minute he makes highlight plays looking like an amazing two way player, the next shooting lazy jumpers and playing lazy D...
Now there's hellfire in the Garden, crying babies everywhere, as Antoine Walker 2.0 launches another long 2, shooting us out of another game 7 in round 1 of the playoffs... 