It all depends really. If your going to trade it on the PC, don't even bother, SR2 was pretty terrible on the PC (aside from the fun little mods and stuff here and there), and it was the control that killed it.
If it's for the console, there is only one factor you have to consider; Do you have any other friends who have it? It's worth the trade alone, i'm not going to lie, but if you have a friend or two who has the game, it makes it about a thousand times better and funnier just driving around and doing random things like beating up civilians, throwing objects at people, doing crazy stunts, sky-diving off of buildings and out of planes and helicopters, and my personal favorite, 'Plane-jousting'.
So, all in all, if your going to get it for the console, by all means trade it in, and cross your fingers hoping that a friend has it too. If it's for the PC, don't bother, and try another game instead