The winner would be very different on a SNES forum...
That said, having played one stage from both games (emulated, do not own yet), Soldier Blade wins, no contest.
Soldier Blade has perfect music, perfect graphics and perfect gameplay.
Axelay is a nice tech demo, but the music is lame, and the control is sluggish.
That's just my opinion per Stage 1 for both games, though.