2wd a lot tougher in the transmission department, and cheaper to run, BUT need to be careful in the wet, as they are wild, more so when tuned, just treat with respect(a lot).
I still get nervous in the wet(with the car!!), got to use your ears a lot and listen to turbo spooling.
4x4 a very good car, very safe predictable handling.
If you can why not try to blag a drive in each as they drive different so you can see which you prefer to drive.
For the same power 2wd will always be faster due to transmission losses, but off the line up to around 35mph at least the 4wd has the edge.
There is less to go wrong on a 2wd, if you are going to want to go to silly power levels, certainly 370/380 up then 4x4 gearbox is not going to have a good time, and is majorly expensive to get a better one.
tabetha