Noisy? Can't be any more noisy than my Cobra.
I don't think any of these types of cars are good grocery getters, and the appeal to me would be that it is rough, loud, mean, etc....If you're looking for comfort, there are better cars for that. If you want raw racing car on the street, how could you go wrong?
As for HDR, I would have to agree that they look to have a really nice product. I would suggest talking with some of the other buyers to see how everything matches with your expectations. The warranty seems like a nice touch for a completed car. Let us know more as you learn more.