Ummm....every try searching and reading?
1) Homebrew support is good but not as vast as supercards, that is the general consensus. I got DS organize Green to work fine if that means anything.
2) Near perfect, I don't think there is a game you will want to play that cannot be ran perfectly on the m3 lite.
3) DS Compatibility = the same as supercard, except maybe right now it's actually better because the new software for m3 already came out while supercard is still a tad behind.
4) Easy to use to me, but then I've used M3 from the beginning with a m3 sd....learning curve is maybe oh.....10 minutes....you determine if it's easy for you.
5) Save system is similar to g6, it saves games in battery powered sram and writes them onto the micro sd card when you reboot.
6) Extra features, plenty, ebook, integrated moonshell, skinnable interface, whatever. Plenty of things to look at.