I've had my (actually, when describing it in mixed company, it's my WIFE'S car) HyHi for a couple of months, and have noticed that the 4-wheel drive (rear wheels) kick in quite a bit of the time, mostly when climbing hills in conjunction with curves. I think this is probably a good thing handling-wise, even on dry roads. I think that, for the extra cash, it's probably a good thing to have "just in case". And, when you sell it, you will probably recoup most of the extra money spent.
A GREAT car, and IMHO the best choice on the market for an SUV.

Mountain driving really hurts mpg!