for starters my wife and I have two 04' 700EFI's and love them. they are not water tight though as you said, there is a vent tube on the top of the clutch cover that goes under the gas tank/front fender plastic and if you hit a water pit/mud pit to hard or to fast water usually comes in through that vent tube causing the belt to get wet and slip. I don't know why you would tow them home though, usually you can just pull the clutch cover drain plug to let the water out and your on your way again. The water intrusion issue is probably one of the only things I don't like about my polaris, I am thinking of making a snorkle for that tube so I can go in the deeper water without getting water in that tube.

I rode with a Yamaha Kodiak this past weekend and It went through just as much as my 700EFI, I think it was a 400 or 450 kodiak. I would stick with either the yamaha or the polaris models though.

 

I'd suggest the Kodiak 450. I bought one for my wife and she loves it, for that matter so do I. I try not to take it but do sometimes when I go wtihout her. She's small only 5'2" and has no problems with it. She had previously never hidden and now she hitting the mud holes, climbing over stone walls and anything else I through at her. Which ever way you go have her try it out first. Good Luck with what ever you pick they are all good machines these days.