One offers real knockers and the other offers fake knockers.
One offers both standard and widebodies and one offers only standard bodies.
One consistently offers games with subways and under-playfield troughs, the other almost never does.
One offers both Italian and non-Italian bottoms, the other offers only Italian bottoms.
I'm glad JJP is around to counter the radical homogenization and defeaturing Stern has instituted since the 90s.