The chain is going to be needed regardless for snow and ice duty.
My 318 with ags but no chains required careful handling in the snow to prevent it from being stuck.
My son's MTD 990, with mere turfs and chains is a monster. (wow, two chances in one day to show my son off).
http://www.youtube.com/watch?v=bEQtE18e7MU
So, turfs with chains are just fine. All Trails with chains are great too, and will be better in just snow without chains than just turfs.
You will not tear up your turf leaving the All Trails on all year. I leave my loaded ags on all year and they don't hurt mine.