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.