LAST EDITED ON Oct-19-09 AT 09:52PM (MST)[p]First off, Can Am and Arctic Cat are NOT the same.
Second, the 400 that struggled at elevation was not jetted for the elevation. If jetted right it would have done just fine.
My experience with ATV's includes over 5 years of renting out 20 ATV's and putting over 4500 miles in a summer on them. I buy new machines every year. For the last 4 years the only 4x4 machine I run is the Can Am (Bombardier) Outlander Max 400. I rarely have a warranty issue and they hold their value very well. They are capable of taking two people, have a high and low range and should be able to handle anything you intend to do hunting. They are an excellent machine. I also run yamaha grizzly 350's as my 2wd machines. Also an excellent machine. I imagine their bigger bore machines would be excellent as well, but have no experience with them. I do have experience with Polaris and am not a huge fan. I have had good luck with their Rangers, but not so good luck with their sportsman 500's. I had a ton of warranty issues with them.
Lastly I rent my machines at 8000 - 11,000 ft. They are jetted for that elevation and run great. Even the 350's will easily take a very large man anywhere he wants to go.
The reason I run the machines I do is because of reliability. If I have a machine that goes down and has to be in the shop then it costs me lost revenue by not being able to rent it. I run what I do because the are dependable, capable, and easy to ride.
Good luck.
BTW, I have both machines for sale right now. PM me if interested.