I've been playing the English version for a couple of days (thanks demi), and I've been really enjoying it so far even though that I hated the original FFVII. The story is pretty good so far (though nothing groundbreaking or surprising if you've played FFVII), and having a cheerful, optimistic protagonist such as Zack is a refreshing change of pace in a Square Enix RPG. The game has some pretty high production values for a handheld RPG. The FMV sequences so far have been pretty impressive, and did a nice, unobtrusive job of progressing the story forward.
I have mixed feelings about the gameplay. The combat is fun and fast-paced, but I really don't like the how unsystematic the DMW system is -- which makes you perform limit-breaks randomly. The boss fights so far have been pretty easy, if a little frantic at times. If you like a challenge in your action RPG you might want to start with Hard Mode from the get-go.
I am really digging the music so far. I've already heard a couple of FFVII remixes so far, and they were great. The new stuff is pretty good too. Though at times Takeharu Ishimoto's work sounds a little too much like elevator/lounge music.
After playing Chains of Olympus, I've honestly found the graphics slightly underwhelming. The character models and facial animations look incredible, especially in cut scenes. The backgrounds and environments, however, look like they were ripped from a Dreamcast game. Which is not to say they are bad (especially if you consider the hardware of the PSP), I just expected a little more from Square Enix. The game's presentation is slick, and does a nice a job of modernizing FFVII's blue theme and menus. All in all, this is definitely one of the best looking PSP games.
Bottom line: You should definitely try this if you're an action RPG fan. If you're a FFVII fan, you're obviously going to enjoy this so much more.