[Pilot_51]

R4 is still much better. I bought my R4 for under $40 (including shipping and microSD-USB adapter) and a 1GB microSD card for about $13 (including shipping and miniSD, SD, and SD-USB adapters), which comes out to $50-$60, less than half the price of the DS-Xtreme 2GB even if you get another 1GB. a 2GB microSD goes for about $30, which would put the total price at about $70. My microSD is pretty fast too, at least faster than a hard drive as far as I can tell.

AFAIK there isn't really any difference between R4DS and M3 Simply other than the firmware and label, but it looks like R4 has the better price.

Edit: One more thing, the DS-Xtreme 2GB can't be the final nail in the PSP coffin since the total price of it and a DS is $260, which is $60 above the price of the PSP now. DS + R4 + 2GB (1GBx2) microSD = $190, which is a few bucks cheaper than PSP, so if homebrew is going to be the final nail it'll probably be the R4 doing it.