compared to most cars yes they are good in snow, but compared to other AWD cars no, id actually say they are some of the worst. audi has a far superior AWD system, in general they have a significant amount more grip. the e30 325ix is much much better than any subaru ive driven in snow, probably due to the power distribution and being a far better balanced car. ive driven an old ass 323gtx that was as good as or better than the best performing subarus ive driven, same goes for the celica alltrac.
id say subarus suffer mostly from their poor balance, they understeer like a mofo, you have to do like 4 scandi flicks to enter a corner with any decent amount of rotation, and ive driven a lot of subaru's, wrx's sti's one with studs, outbacks.. i worked at a import auto shop, and have been around ice racing and snow cross type events a bit.