It won't cover you for other possible risks like legal fees, personal liability, delays etc. and only you can decide whether or not you need cover for such eventualities.
we've used getcover.com for the past couple of years, the cost of a couple (allowing for the VHI plan B) was approx €60 for a couple.
So far we've never needed to claim, so I can't say how the claims process works!
If you're going to the US I definitely recommend insurance, its too big a gamble not to have it.
I have bought multi trip insurance in the past with aceinsurance. This year I went with getcover. I have not needed to claim with either company so I can not speak about the pros/cons of either. I went with getcover this year because for virtually the same price they offer better cover.