Heh... quite enjoying this thread though, it's like those schoolyard arguments about C64 vs Spectrum, only more entertaining...
I loved Uridium 2, but it's hard to compare it (or Apidya) to Battle Squadron as its not a verty shooter
My top ten Amiga shmups (hori or verty, in no particular order) would probably be:
With shout-outs also to Agony, Disposable Hero, U.N. Squadron and Katakis. But I never really liked Project X...