Sorry to revive an old thread, but I just noticed as I start out with Sly that if you use Sly's up cirlce, the barrel will just bounce off you and you can even use it as cover as you move closer to Drake and explode both your barrel and drake's barrel for extra explodey fun.
I think it should do any, all, or a combination o the following: 1) flatten instead of trip up, taking away the cheap AK combo; 2) not explode when blocked or shot; it should just roll on through and off into the distance, only to fade out after a certain time/distance; 3) like someone else said, only be a ground attack; his air barrel is way worse than ground variant ; 4) if it is destroyed by an opponent, give some sort of reward for their efforts (delayed follow-up barrel?, small AP gain?, something!)
The thing that I wish most players would realize is that Drake has other moves in his arsenal. There has to be other ways to succeed with him, right? I absolutely love his zipline attack. It's really fun to use, and it's pretty effective too.