i just got my Hifonics NX600 (150 watts x 2 at 4ohm) today from ebay (165 shipped). it is definitely better than the old amp i was using before (kenwood 4x50 @ 4 ohm). i'm not sure if i could've got better for the price i paid and if so, what would've been the difference in regards to what i'd HEAR??
to power my front components, I've used alpine V12 series, JL audio slash series, both clarion apx series, US acoustics, Kencrap, PPI, and even Blaupunkt. The above amp in that auction is hands down my fav of all those amps. Now, we without a doubt can question my abilities as an installer and all of those countless factors that make up the grey area between this vs. that. Especially when you consider that I threw JL audio and PPI into that list, it's highly doubtful that I know what I'm talking about when I say that an inexpensive clarion will hold its own against everything I've used so far - if not surpass. After installing that thing a year ago, I have never looked back. The power is always there. The clarity is definitely there. It is hands down the best $150 I've ever spent on an amp. And that's my opinion.