I like the EZ4 vs. the M3 or SC in principle. Now that they've gotten the EZ4L on the street they should start tweaking their software to catch up. I've read of some small glitches in certain games, like a crunchy sound in Metroid Prime Pinball on the menu screens, stuff like that. And of course the Castlevania vid and any other full motion vid sequences in games don't play as well as with the M3, but its not something that can't be improved. None of these problems seem to affect the actual game, and with the exception of Tony Hawk the games that still aren't compatible aren't anything I care for anyway. EZTeam has already stated their short term priorities and filling out the compatibility chart is in there, so theyre gonna get it taken care of. Most who own the card are pretty satisfied with it, and I see less "troubleshooting" in their forum than I do at m3-forum.com.
I have always been pretty interested in the G6 though, because I want the games to play 100% faithfully. The media card thing has changed what flash carts are good for, but I'm weird I guess - I just want my flashcart to play the games, flawlessly. If that means only having 8-10 games with me at once, I think I can live with that. I really don't care if my flashcart can play movies, display pics, or text. I don't really care about a webbrowser, either. Improved SNES and NES emulation in DS mode would be nice though.
Ideally, I'd like to have an EZ4 and a G6 to face-off against each other for a few months until I decide which I prefer, then sell the other and buy a second of the one I like. I like redundancy.