Don't Just Look as Specs...

[Matt Syson]

Hi
The first won't necessarily sound 'bad' as the frequency response is adequate for most instruments or vocals (just a bit lacking in deep LF or High HF).
The noise figure would depend whether it is 'fixed' at that or by manipulation of controls it can be 'improved' although on a 'full' mix it could well disappear in the general hubbub.
Distortion, it would depend on which of the lower order harmonics are dominant and again what you want the overall effect to be.
Having such a wide frequency response of unit B could be a liability in an area of high HF interference.
Unit A looks a bit like the 'raw' specs for a LA2A which has a lot of gain available and was deliberately 'rolled off' at 15KHz due to it's intended role as a broadcast comp / lim where anything above 15KHz had to be removed.
Those specs don't give distortion figures at say 10dB compression which could give a whole new meaning to the 'results'.
While the dynamic range of 86db may not look good, you could perhaps experiment with a signal source and monitor it (set very low) then increase the level (gain) by 86dB, or perhaps safer to have it loud and decrease it by 86dB.
Matt S
Matt S