I tell ya, if I had a 2 handed backhand volley I would switch.
You have a few problems here. The biggest problem is that you will lack reach which when at the net, you need all the reach you can get.
I would also think that it would be tougher to hit with touch, but maybe it is not that much harder.
Volleys are meant to be hit in front of the body. The 2 handed backhand is meant to be hit more parallel with the body where as the one handed backhand is meant to be hit more in front.
I can definitely see it being a disadvantage. I would make the switch. Unless you are hitting sweet a$$ volleys with it, I would make the change. I bet if you switch and do some practicing with it you will laugh about this subject in 4-5 practice sessions with it.
I personally recommend the change. The few weeks of struggling with the change would be far worth it in the long run! Especially as you get older and move slower. You will just naturally have less reach.
Let us know what you decide to do.