I'm going down the PXAX-701 / RUX-701 route starting next week. Will be using the stock HU for the time being while waiting for my aftermarket HU to come in.
Personally, the 701 solves all my EQ, crossover, Time alignment needs while being able to branch the signals into 8 channels.
I can set presets for "driver only", "driver + passenger", "passenger only (for demos)", and associated EQ, gains, crossover levels for SQ, trance, R&B, DVD DTS etc.
BTW, if you want to buy this unit+controller, I think its retailing below 1k for export set.
But think about what you need.. add a bit more and pay $1600+, you can get the Clarion HX-D2 HU that has very very good 24bit burr brown CD quality sound, and built in time alignment, crossover, 5 band parametric EQ etc etc.
I'm getting the 701 only because of future plans to add in DVD capability and to cater for my itching tweaking hands. :laughlik: