I've got an old 2wd Kubota B6100 hydro and I love it. It's probably 30 years old and still starts in 0 degree weather. I've never gotten stuck, but if you are doing work on steep hills, especially pushing snow, you may be happier. Here my recommendations on buying.
1. Condition and dealer availability is a lot more important than brand.
2. Get 4x4 if you have hills or a loader, otherwise spend the money elsewhere. Used 4x4 is almost double the price in my area.
3. Hydrostatic is nice and makes work a little more convenient, but again not necessary.
4. Stay away from anything with a reverse pto
. Attachments are almost nonexistant.