I recently picked up Puyo Puyo for the PCE and found it much more challenging than the Neo Geo Pocket Version. But then I played the Genesis one (Mean Green Something Something... I don't remember) and it was equally hard. So maybe they just dumbed down the NGPC version. Either way, the PCE version has grown on me. Now I enjoy it much more than the NGPC version just because I can play it on a TV, not a tiny screen.
Anyway, that's my 2 cents on Puyo Puyo.