Depends. Put the front in and see how it goes.
When I put my front in, my rear started single pegging. However, my car is a vspec, so maybe the attesa computers had a hissy fit.
Did you do the diff bushes also? I chucked a set of alloy ones in there. Transmits a bit of noise through the cabin, but nothing really to whinge about. Definately improved the shift feel also!
OP. I would think a 2 way might be a bit TOO much.
I also have the same setup. The GT PRO is currently set to medium. I think it's a little too aggressive atm. I'll prob back it off soon enough. Where is your's set to?
The rear definately changes how the car turn's and powers out of corners... In a good way