Re: 8400bh vs 8053 eclipse.
I believe you have to use it with the "Eclipse Commander"....that's if my memory serves me right. That is a very nice SQ geared HU. I think it also has an auxillary input.
It depends on what you really want out of your system, and which head unit will help you get there. Take a close look at this, then weigh the pros and cons of both HU's.
2010 Nissan Maxima SV Premium with OEM DVD/Navigation HU
Precision Power: DEQ-8
Scan-Speak: Illuminator R3004/6020-00
Audison: Voce AV 3.0
Scan-Speak: Revelator 18W/4531G-00
Audiomobile: MASS 2012 S24
Soundstream: TN4.900D, TN1.1200D