Mine still going strong...... Using the SDCard slot instead of USB and find the SDCard to sound better.... With those highspeed and gold plated SDCard the sound even nicer.......

To me data retrieval better with SDCard but maybe it's also due to the usb cable I use it's the one came with the HU and I never got chance to compare with better usb stick only normal one. Using those weather proof hi speed SDCard gold plated type that photographer use.
Anyway that my opinion only and I play flac using iphone and that the best sound quality so far. Too bad the HU don't support flac.

Yeah, a good cd always good but in a car prone to vibration you cannot get the best out of it. Put a good cd on a good home hifi system and then you know how good it can sound.

Suggest you try a few type of SDCard. my case the better SDCard sound better but that me maybe also me ear playing trick on me.

This is my take on this...... media....
CD - Vibration is the main issue even with memory as car moving sure will have vibration and noise injected from engine and others.
USB input - Less vibration, but using cable (unless high end usb cable) there is interference (EMI/EFI) to deal with unless plug in direct but troublesome as the usb input at the back not the front plate....
SDCard - convenient as in front. Also no cable as direct plug in. With a good SDCard less worry of data loss.

Also, Car enviroment need to rely on processing such as time alignment and others. Not that easy to adjust sweet spot as listening position are fixed and speaker position are fixed and cannot simple move around like home enviroment.

What I did to test that time was I took a CD and I ripped and put it into a 2 GB USB stick and also a 2 GB SDCard. Slot all into the HU, CD into CD slot, SDCard into SD slot and the USB into USB cable. Found I like the SD Slot the best so decided to use it as the main source.

This post has been edited by scsoo: Apr 21 2014, 10:27 AM

Maybe the Boss one different.. encoded with security encrytion and his system plays encrypted file.
Put the file in our normal player will hear "this recording will self-destruct in 5 second" and booom... there goes our HU...