I'm wondering why you ruled out the Parasounds?
The New Classic Line is awesome, and I think the Halo's are in the same league as more expensive amps like Theta and Krell. I've used an old HCA-2205 for about 8 years, and have no intention of replacing it any time in the next decade. I'm biased, but it's a good amp.
In any case, most amps are pretty neutral if designed well. For me, looking at similar amplifiers in power rating and price, I've always found it useful to also consider their current output as well.