Question about quads

[Tater]

I've been reading a lot about quads and am very interested in buying one very soon. My question is on the fuel system: carb vs. EFI. I know EFI is generally easier to start when the weather is cold and operates more efficiently at varying altitudes but how much worse, really, is a carbuerated (sp?) engine? Is there an adjustment, or maybe a bolt on kit, I could make on the carb to make it run better up in the mountains then change it back when I'm down in the lowlands? I know, with my old truck, I could adjust the butterfly valves and make it run better if I was going to be in the mountains for more than a day or two; just wondering if it works the same with quad motors. Thanks.

By the way, I'm leaning toward an Arctic Cat, probably the 650. Everything I've read says it's just about the best deal out there. Jack of all trades, master of none. About the only bad thing I've read and heard from friends is that the steering leaves a little to be desired mainly due to a lack of power steering and lots of feedback on the trail leaving a person pretty fatigued at the end of the day. Any input on the Arctic Cat? Thanks again.