Pioneer >>>>>>>>>>>>>> Sony.... the pioneer has time alignment, 16 band GEQ, 24 bit DAC, 5v preouts (which are pretty high for a HU, only one ive seen higher is from Eclipse with an 8v), CD SNR or 100 dB... its extremely fun to play with (managed to find a place that had one installed

i enjoyed that hr very much lol), its got a great interface and is very easy to use. Doing normal stuff while driving (changing station, changing sources, volume, etc) is very easy to do, the time alignment and frequency cutoffs for the sub channels and all those type features are easy to do but you should do it while parked anyways (so you dont hear road noise)....
i went to Pioneer's webby and dl'ed the manual and read most of it, so i knew how to do most things when i went to go play with it instore lol. i suggest reading the manual so you can see if its interface is laid out in a way you like. i highly reccomend playing with it in a store (that is with any HU however), because once you play with it for a little you will know what you like and dont like.