EFI can be good and bad. On the good side you wont need to mess with the carbs jetting when it warms up or gets real cold. On the bad side, I believe the year arctic cat you are looking at has a battery. your EFI will run off this battery. If you dont keep the battery in good condition or if it fails on you, your EFI doesnt work right = SLED doesnt run right. I personally perfer non efi because they make an engine much easier to fix. I would Personally buy the Polaris, but I am also biased. However If given a choice between an EFI Polaris Vs. a Plain AC i would buy the AC to stay away from EFI. It all depends also on where you ride. EFI is nice in the mountains but not as beneficial here in MN where there is little elevation change. If this is your first sled I may look for a 440 or 500. They are lighter and can be just a quick out of the hole as a 650 or 700... You can also get around jetting changes on a non efi sled using Dial a Jet or similar product...Just My Opinion
L8R,
Darkstar