I have the JVC Bongiovi HU. I've had it for ~2-3 months. It's a great piece for the $, but no where near the original retail. If you like to customize your sound, you are very limited with this unit. It has a nice Sub level control, cross-over, and slope built in, but that's about it for customizing sound. Besides that, you simply get "treble" and "bass" levels (no frequency EQs). I suppose one can keep downloading the custom Bongiovi files until you find one you like, but that would be somewhat a pain also. In the end, I'm pleased with my purchase, and you get a lot of nice features for the $. If you like to custom you sound, I would look elsewhere. Don't think of it as a $600 unit. Think of a nice $200 unit.
The 5V pre-outs in the F/R are nice. The 2V on Sub out = not-so-nice.