The pioneer will be a much cleaner headunit than the sony one. If your looking for SQ you can get a lot better headunit for that money. I guess pioneer is a good mix between looks and features and sound quality though. The 8400 is a neat toy, but i am sure it gets boring fast. My friend bought a 6400 a while back and he was bored with the graphics in like a day and wished he hadn't wasted his money going from the 4400 to the 6400 because other than the way they look, the 2 headunits are identical as far as power/features goes.
Headunit: Eclipse CD8443
Front Stage: Boston Acoustics Z6
Rear Stage: Boston Acoustics Pro 6.5
Subwoofer: Dual JL 10W7 Sealed Enclosure
Mid/High Amplifier: JL Audio 450/4
Subwoofer Amplifier: JL Audio 1000/1