The REASON 4V+ pre-outs are a good thing is for gain settings on your amplifier. If you have a 17-20 foot run of RCAs and a head unit putting out 1-2V, you're going to have to crank up your gain to get a respectable output from your amp (up to source voltage,but before clipping). If you have your amp cranked up to 50-80%+ to match your source voltage......you will most likely introduce noise into your system. Some amps will pick up alternator whine, ground loop noise, hiss, etc if the gain is cranked up more than 50% in a running car environment. (Bench testers need not apply here!)
I agree, the Alpine is the better unit. That being said, I have a cheap Pioneer Deh-1200MP that's going strong.