Demographics indicate that Subaru owners are also likely to have a BMW in the same garage (or is it vice-versa?).
We just happen to have a Subaru WRX STi that has been modded with Turbo upgrades, swapping to a front mount intercooler instead of top mount, many suspension parts have been replaced with higher performance parts and the list goes on...
With the AWD system and the various ride and handling adjustments the STi offers, it's definitely a car worth driving and mods as everyone knows here are pretty much endless. I'd have to say that in the snow, the STi can't be beat if both the STi and M3 were wearing a good set of snow shoes, but that's not the road condition most people will be comparing these two cars in. Watch the Rally cars with guys like Travis Pastrana and Dave Mira - those guys rip around on the snow tracks like they're dry pavement. You wouldn't see an M3 out there doing the same. With that said, I'm still a huge M3 fan myself so it's a good thing I'm not planning to become a Rally Racer.
Since I just sold my M Roadster, I'm now on the market to eliminate the awful performance bug that has bit me and I'm looking at an M3 for a replacement. Since it's not AWD, it's the single potential deterrent for me since I have a decent commute to work and I've always driven an AWD or 4X4 for my daily driver. I've got an Acura MDX SUV now and have no worries, but if I get an M3, I might do so on a trade. Garage space is limited.
I'm on the countdown to when the dealer opens this morning. I hope my Sales Consultant is working today!