The main benefit that I can see with the xi is actually the ride height. With snow tires on the car, getting going shouldn't be much of a problem (sandbags in the back if it is). I drove around in some pretty serious snow and ice this last winter with my blizzaks and only had one problem with my non-Xi - ride height.
My car is just too low (stock) for some of the snow we got and I didn't want to risk plowing an iceball with my front lip. Concern for my front fender was my biggest limiting factor. That being said, my family has a second vehicle with AWD and snow tires, so I'm not as concerned about conditions that prevent me from using the E46.