At one time I actually had a Great River NP2, the older DMP
2, a Behringer MP2200, and an Earthworks LAB102 all set up side by side in my studio....also a Mackie 1202 VLZ mixer.
I could imagine that I could hear slight differences in response, but it was definitely not a clear-cut decision that one was "better" than the other.
The Earthworks seemed most "transparent", which I regard as the most important feature.
The Behringer and DMP2 both sounded quite good and "neutral", but with perhaps a small loss of crystal transparency.
The Mackie 1202 sounded very "clean and crisp", but almost as if the high frequencies were boosted slightly.
The GR was definitely the most "colored" of the group, almost sounding slightly like a very slightly overdriven tube amp. It sounded very good. I can see why people like it, but it was definitely not transparent.
All these differences were so slight as to be in the "borderline imaginary" level. And I knew exactly what was testing and was able to A/B switch back and forth many times. I don't think I would ever be able to confidently identify any of them in a blind test; and certainly not in an MP3.
Just my opinions; blame it on my crappy ears. I sold everything off except the Mackie and an Audio Buddy.

I usually just use the built-in preamps of my VS1680. So many other things made such a vastly greater impact on sound, that I just quit worrying about preamps.