If you liked FFX and Charlie's Angels, then X2 is for you
Otherwise if you don't want to see the serious and well portrayed character of Yuna become one of the stereotypical anime/manga fan service girls (which RUINED it for me) then don't touch it with a 10ft pole. I did like the grown up Rikku a bit, but otherwise found X2 to be a fast cash cow for SE to milk the FFX fan base as much as possible. I agree with the comparison to bad fan-fiction. Was relatively fun, but wasn't worth a second play-through imho (unlike FFX which I replayed about 10-12 times over the last 6 years)