SnoWest test rider Steve Janes rode the 2017 Summit 850 in January in Canada. He had this to say of the tapered tunnel and rider ergos:
"Upon mounting the sled, we could tell the ergonomics of rider position was greatly improved. There was more room forward, less girth between your legs and a very natural feel in both sitting and standing positions. A beveled tunnel and seat design allowed free movement from side-to-side of the sled. You weren’t crawling over your seat. You were shifting and sliding. And an open foot stirrup allowed you to get even with your steering when you moved forward on either side."
If you want to see the rest of his comments, check out the upcoming March issue of SnoWest Magazine.