I hunted for a long time until finding a very clean used tractor at the end of 2018. The main reason for going with used was that I wanted to avoid the regen. Complaints haven't been as plentiful the last few years. I still prefer to run at lower RPM's for some work rather than wide open throttle (required for the DPF).
The size is something you'll need to think about because you know the tasks it will need to perform. Snow hasn't been very plentiful here recently, but my tractor handles an 8' plow that was repurposed form a 3/4 ton pickup.
Any of the major household name brands should be OK. I was open to other brands when I shopped, but Kubota has been preferred because of good experiences with them - and Messicks is 5 miles away when I want the official filters, fluids, etc.
The current tractor has a cab. After 4 open station tractors it is great. Pollen, deer flies, bees, dust and other irritating things are on the other side of the glass. Winter work can be done in a flannel shirt. If the schedule requires it I can go mow 3-1/2 acres AFTER taking a shower and wearing nice clothes, park the tractor and go to a restaurant.
Forks on a QA frame work better than forks on a bucket. The load is closer to the tractor so the capacity isn't as reduced. It's also better for seeing what you're doing. It still takes seat time / experience to get really proficient. Some guys have added remote cameras to help them.