I can say the AWS is a plus in snow. I have a blade on mine, and a good neighbor says he wouldn't have anything else with his behind a blower, sweeper, and his blade.
Amazing what traction one can find just by turning the rear wheels in a little different direction. Hard to describe. The AWS was something I was tentative about, but so far it has been bullet proof.
I think highly of the diesel too (smell on one I bought made me switch back to the gas as I just didn't like it, and didn't want to try to get used to it - but wish I could have) for its fuel efficiency and many hours of performance. They seem to get better with age. Did some work around 455's with hours close to 2000, and they seemed smoother than the low hour ones.
But have an X485 AWS and think I have the best of 'all' worlds for a mowing tractor with some snow plowing (my son uses it in the winter for snow while I use his 445 with the 519 cart for picking up leaves).
Another plus for the AWS is how it turns when on a slope. When going along a slope that is steep, my older regular steer tractor would slip the upper wheel if I turned uphill. The AWS just turns and goes up without any wheel slip, as it seems to scoot the rear wheels around under the rear to keep good traction. Again, hard to explain, but impressive to experience.
Another plus with the AWS is how much less backing up (reversing) one does, as turning corners and turning around is so quick and easy. That is probably the first thing I noticed when I had my first AWS back in 1998.