I've got a dslite with a m3 mini sd, passcard2.
I love the dslite, and would love my m3 except for the following reasons.
1. the card slot is in the front. This may be a plus to most people, but I've had the card come out accidently, and my children are 6 and 8 so thats not a good thing.
2. The menu, I still don't like it even from the original movie player. I want to boot up to the game list, not the main menu, then hit a, then select game, hit a, then hit a to load the save game.
3. Cost! the m3 is still a pricey beast! if you are only going ds games the m3pro does all the ds software but loses gba compatibility for less money.
Later,
dabone