It has been stated multiple times here in this very thread, but it seems to be overlooked:
The differences you think you hear are likely due to problems with your comparison methodology and not with the actual products.
You MUST LEVEL MATCH for any comparisons between these two amps to be valid.
(Then in addition to level-matching, you really need a way to switch quickly between the two amps. Disconnecting one, connecting the other takes too long. And then, in addition to THAT, you should also compare without knowing which is which.)