Audio is a personal thing, including what sound quality means, but you asked for personal, so I'll give it....Audiobahn is more glitz than go (IMO). Their products tend to produce what they state (but not a lot more). They seem to do well in reliability - at least I haven't heard a lot of horror stories. Still, I think you'll be happy with that amp.
For me personally, I'd still go with the Power series from Rockford, like this one
http://cgi.ebay.com/ws/eBayISAPI.dll...=5754708270&rd
Rockford's punch series is of lesser quality (closer to Audiobahn IMO). The power series always outperforms the specs - or at least every one I've seen.
Or how about this one:
http://cgi.ebay.com/ws/eBayISAPI.dll...757044581&rd=1
I ran Alpine amps for a couple of years (they are now in my son's car and still performing flawlessly) until I upgraded to a 3-channel Xtant amp (two stereo channel for the front speakers, one mono channel for the woofer).
BTW, I ran Infinity woofers in my car for a couple of years, and IMO they have the best quality/price ratio for woofers on the market. And if you ever decide to upgrade the front speakers I would just as strongly recommend CDT Audio. Other brands may have more flash & name, and even have better sound quality, but CDT are exceptional when used in stock locations because of their sound dispersion patterns.
One last thing...600 watts and two 12" Infinities and you will overpower almost any speaker you put on the front stage (if you're going for balanced sound quality). But then again sound is a personal thing and how much bass is too much is....