I'll throw in an unbiased .02 cents as I ride one of those "Other" sleds...
Rode a stock 2010 M8 sno-pro today. Ran strong. Quick to rev up and pulled nice.
Then rode a 2009 M8 stocker. Yowsa...I dont wanna say it was a slug but comparing the motor on those two sleds in stock condition is unfair. The 09' pulled lazy. Felt like a 700 compampared to the 10' IMO.....
For what its worth my XP with a buncha compression via an RK Tek head, Rooster Built clutching, can, re-jetted and geared down a tooth burning a a fuel mixture that yields about 100 Octane could only pull about 1 to 3/4 sled lenght or so out of the hole on the new stock 10' M8.
The M8 feels really fast as the clutching seems to hit hard and the sled really pulls....My XP clutching feels like a slipper clutch and dosent have the drama and exciting "Hit" of the M sled.
That tells me if the M8 guy does essentially anything its without doubt a faster sled than my XP....That 16" Doo' track sure does help a guy out coming outta the hole though!! I also outweighed the M8 guy by 80 pounds.....
New M8's are strong as horsemeat in stock form for sure...09's M8's comparitively? Not so much.
I have another buddies 09' M1000 in my garage and we ride every weekend....Once up to speed and climbing? Game over for any unmodded 800 including the 2010 M8. That M1000 is a BAMF' A sure fire trackspeed holding mountain scaling beast.