I just bought a 2008 HCH a couple of weeks ago. Yes, there is still the full $2100 tax credit if you put the vehicle into service before the end of this year. Starting January 1, 2008, the tax credit gets cut in half.

Living in Salt Lake, I've had the occasion to climb some of the canyons nearby (4500 feet climbing to over 7000). The car does just fine with them. It's not so efficient on the uphill (obviously), but I think it more than makes up for it on the downhills. At least, such has been my observation.

As for the HCH vs. the Prius... well, there's a few discussions hanging around here you can search for. I was faced with the same decision. I chose the HCH because I liked the displays better, and I found it to be more comfortable. Of course, all these are my personal preferences. The two cars are close enough performance-wise that it really does come down to personal preference. Either way, I don't think you can loose.