To the OP: can you describe the set-up you heard that leads you to conclude that the LMs "sound terrible"? I've heard quite a few. I've no problem if someone were to prefer, say, the ARC or Manley house sounds; that's simply a matter of taste. But "terrible"? I can only imagine they were being asked to drive low impedance multi-driver speakers, or the source was poor, or a tube was failing, or something else.
BTW, I would also hesitate to necessarily blame an amp for humming -- if there's DC on the line, the transformers will probably hum...
BTW, I would also hesitate to necessarily blame an amp for humming -- if there's DC on the line, the transformers will probably hum...