The popular opinion is that the Messiah 2 is still the best mod chip at booting all ps2 games, however ask anyone with a dms an they'll tell u that it beats the M2.
As for the other chips, The M2 is cheap enough to compete with all of them so why consider anything else.
If u really think that yr gonna use the extra features that dms offers then pay the extra, if u just want a chip for booting backups go for m2.
Regards
