keerym,
check with your dealer. Many have been already and will show you info.
I did look at GT/GX replacement, but only briefly. Unfortunately it appears not to be a return to old 318 supremacy. The frames are ~3.x mm vs the 4.xmm of old 318s, current X series, and new X700s. So won't be moving the boat with it.
On plus side, I think it still had diff lock, and now offers HDAP tires. No 4wd though, so still needs chains. I think a little more HP, biggest deck was around 54", and new seat with built in grab handles.
Again, I personaly think dealers are one of Deere's advantages over competition, especialy on consumer equipment end, so pay them a visit. Then perhaps you can give a better update than this! In meantime, sorry for not more detail.