To add to that I rode my buddies hopped up M7 and it pretty much took flight while climbing. But I didn't get any further on it than my Apex.. To each their own..
Change the track to Challenger Extreme and in anything short of 4 feet of powder it will hang with the other sleds just fine. I have mine setup very well and it rips, I can't imagine what it would be like with a turbo. Its nice not to have to dick with the clutching all the time as well. The other day my buddy with his XP couldnt make it over a hill that I was blowing over no problem until he dialed in his clutching. He kept looking at me going by like WTF!
To me the only strike that the Yammie has against it is the extra weight and the 2 stroke really only has light weight going for it. Decide what is important to you, ride em all and then decide.