well grafs new kernel is for linux so its not really relevant. Comparing kmeaw to ps3mfw is completely irrelevant because ps3mfw is customisable, as long as you select the right patches it'll function the same as kmeaw and the changes will only be cosmetic.
as long as you install the right patches in your mfw it'll work. Might want to hold off on graf's linux kernel though I tried compiling it last night and with the asbestos bootloader there's no way to select a kernel so if you install it and it doesn't work or something goes even slightly wrong your install is pretty much fried as you wont be able to boot it to fix it.
His bootloader / .pup should be nearly ready though apparently it's based on petitboot so linux will be much easier to boot after then.
PS3MFW just freaks me out a little because you lose the reassurance of md5 checksumming. every created custom file has an internal timestamp and thus a different checksum.
probably would never happen but i'm paranoid about a bug or a glitch somewhere. i should say I made the files under a windows wrapper and not the native linux so that does make things slightly more likely to break.