Yes DVD9 = DL
Not all PS2's can handle DVD9-R discs in fact most can't it is too much for the drive to handle and in most cases will lag badly and stress the laser out
DVD5 rips will work ok though
EDIT
Good RIPS will not take anything from the game, these will either take alt language files out or just span the game over 2 or 3 discs, I have a few rips in the compat list for ESR
None of the ones I have tested had any cut scenes removed, a few are spanned over more than one disc, the only game I did burn onto a DL DVD was xenosaga Episode 1 but that lagged on loading and very bad lag in FMV so I found a 3 disc rip kit and played the game perfect from start to end
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