I was told by the Yamaha dealer that you have to be under 5 MPH when you engage the Grizzly's diff-lock. I've engaged by Prairie 650's at over 10 MPH without any problems!

 

I always stop before engaging mine anyway, just in case. No sense screwing something up. I will put it in 4wd though at speeds up to around 15-20. You can look at the diff lock thing from about a hundred different angles and find good and bad points about both. For me, the difference was miniscule seeing that they both actually can lock, and that was enough either way. When you get two machines as closely matched as these, things start becoming fairly nitpicky. As far as the center of gravity goes, almost every quad ever made has a gas tank mounted in the center position. The kawasaki does probably lower its center of gravity, but also puts it more rearward thus less weight on the front for hillclimbs. Now thats being pretty picky. It also wouldnt be something to sway me. Just showing how if you want, you can always dig up some little nothing to pick out.

I do like how the Kawasaki's struts hide the outer cv boot from damage. Good design there. I never found the griz to be real tippy. There are better quads for sidehill stability, but a set of aftermarket rims and 12" tires makes it an incredibly stable quad. I put just regular offset ITP's on mine and added my 27" claws and it made world of difference. Probably better than my AC was when it had the claws on it. I don't know though. An AC is about as stable as you will find.

The thing with the grizzly is that it is tall, and if you aren't used to it, it has a wierd feel to it. It took me a couple weeks of riding to get used to the different feel. Now its just second nature. Same would go for any other quad though. Except maybe a king quad. I don't think I could ever get used to the light front end.