Looks to me like the seat is clearly higher on the new series. You can see the bottom of it over the top of the fenders where on the old one you sat down in more. Better visibility though height I guess?
I think you're spotting the front edge of the seat better because the fender grab handles are way smaller on the new units. (Is that an improvement?) The grab on the 4000 ten is kind of blocking the view of the seat front. The tranny/rear end are the same - as is the seat and suspension (I checked part #s). The floor/deck is a new part # but I think essentially the operator's positions are identical.
Hey I thought the Deere's had left the good looking stage when the 6000,7000,8000 TEN series had left the arena. Those along with my 970 and 990 are the best looking tractors Deere ever made and some of the best built too.