Well, in my experience, last winter I bought a 08 d7 with a 155. Two of my bubbies ride Doo 800s and one has a 08 d8. What I learned was this- as with anything, the brain that is riding is the most important part of this equation. Sure, 10 hp or so is cool to have on your buddies, but unless your seeing how far you can climb a skyscraper, that little bit of power is not an issue! Chassis and the rider's abilities that make good use of the power is what's important here. But to answer your question, I would not be scared of a 7. Mine kept up with all those 8's last season. My 7 is the third 700 I've owned- started with a 99 that I put a 144 under, then a 02 with a 144. The 700 in my opinion had the RMK for a reason- it was king. Now, the 7's still hold their own very well. Regardless of how big you go, its still about the techniques!!