I just meant hearing a difference in the dynamic range.  I went from using a Motu Ultralite, which I never got working without serious snap, crackle and pop...to a Focusrite Saffire LE which was rock solid stable but doesn't do 64bit worth a dern...to the M-Audio Fast Track Ultra, which so far is waay better on all counts.  Stable, fast and sounds great.  My system has never sounded better.  If the Fast Track has a deficiency in "dynamic range" I cannot hear it.  It's a wonderful interface. YMMV.
 
PS:  I don't mean to start another "I swear I can hear what bats hear!!!" thread, but I would imagine that most all the decent to totally pro interfaces these days will give you a stellar listening experience.  As ragged as they are...rode hard and put up wet...I still trust my ears over numbers on a piece of paper.  Here's a for instance:  The EMT 250 reverb has a very limited dynamic range compared to most modern day reverbs...yet it still sounds fantastic and does what many other reverbs just cannot do.  My advice is to take any hardware (or software's) specs as a guide to help you contrast and compare other like units...but LISTEN to all of them before you buy.
 

Hi Frank

I went from a Delta 66 to the Layla 3G  and it was a *very noticeable*   and  *surprisingly large jump*  in audio quality, fidelity and dynamic range - and Im pretty sure the AP2496 wasnt as good as the Delta range.

Im not sayaing there is anything wrong with the FTU, but the guys at EchoAudio  *dont*   " fluff their specs up "  -  like RME and Lynx, if anything, they underplay their figures.

Specifically, for these  2  units:-

If your main goal is maximizing audio quality combined with  lowest possible latency, get the Layla.

If your main goal is easy portability / external-non-PCI-connectivity, get the FTU.

Whislt I am clearly biased, truthfully, you will be very happy with either unit.

Tom