m3p, what's p? pro or perfect?? pro does not support gba game, and i think currently only in chinese... if u dun mind them, go 4 it...
i have used m3 perfect mini sd before.. it is one fine product, on fat DS that is... but on lite, either g6l or ez4l.. i simply do not like the extra 1-1.5 cm
i own ez4 lite (supposedly have the same features with ez4), it's an okay product -- physically ppl like the ez4 build (not the lite one),.. gameplay minor slowdown on some games & here's the compability list >>
http://www.ezflash.cn/list.asp
and ez4 kinda lacks homebrew apps support coz the fat fs access is not supported by chism's fat... now personally i used to worry about the homebrew part.. but after try a few homebrews on m3, i could live without them... except for moonshell & scummvm and they work on ez4
as for supercard,.. i play around with friend's sc... simply, worst UI ever... ugly & not skinnable (right?)... but hey, it works...
so, assuming that u own the good 'ol phat ds, if u still can get ur hand a piece of m3
perfect minisd, go for it...
otherwise,...
if u want more homebrew -- maybe SC (coz it is harder to make homebrew to work on ez4)
if u like cute yoshi skin like the 1 im using now -- ez4
i'd say m3 pro is a no no, coz it's in chinese & no gba (i personally dun mind the gba part -- i would go for the next cart the only got nds and snes support) but it's in chinese.. i bet u'd hate to keep wondering, "oooo, what does this button doo??"