Hiya.
I have pxah100 in the missus wrx and pxah800 in my e53. I can't compare to other products that do processing but both worked well for us.
If I. was you I would not buy the pxah100/800 unless you have a need to.
We had problems in each car, that the processor solved nicely for us. Smoothing out low frequency response curve and killing some nasty resonant peaks was biggest difference for us. There are better ways to solve such problems, such as bracing, damping materials etc, but I didnt have time or skills to do that.

Where in oz are you? I'm in Melbourne. I can possibly demo for you given enough notice..

cheers
scott

Sent from my GT-I9300T using Tapatalk 2

__________________
2019 G01 3.0d ,2010 E70 3.0d, (RIP 2006 3.0d e53)