As a veteran of every game up to XII, I have to say I like this game.
FFX was painful. It had gameplay elements I found painful (the sphere grid), idiotic complications to the weapon and armor system (admittedly, customizing all your stuff was a cool idea), painful voice acting (over half of it was narm save for Auron, who got all the lines that DIDN'T suck), and the general story tone was depressing. The ENDING was so much of a downer I wonder why I bothered playing.
FFX-2 was fun. The gameplay was familiar, simple and streamlined (Leveling, yay!). Also, thogh I like collecting weapons and armor, the dressphere system was very intuitive (though the ingame justification is shoddy at best), the voiceacting, while narmy, was more amusing than facepalm worthy (considering the tone, I believe it was on purpose), and all the dramatic scenes actually seemed dramatic (some of FFX's early scenes were just horrfying to watch, at least for the first third of the game, where the narm was highest). Also, the story largely removed the bad taste of the Neon Genesis Evangelion style "why did I even bother with wishing for hope to prevail" ending.
Bonus points for confirming LOTS of stuff hinted about in the backstory, at the fact it all fit, not to mention a love story that didn't feel forced.
(No offense to Tidus\Yuna shippers, but the romance was pretty slapdash and formulaic in it's setup, and I largely consider FFX-2 to be the Authors Saving Throw in regards to salvaging it.)
My love isn't total. It had some lazy cutscene animation (Rikku in Zanarkand Ch.1 is a good example), and sometimes Yuna picked up the Narm Ball Tidus seemed to be carrying, and while I loved the gameplay, it had a tendency to be TOO easy (unless you were in the bonus dungeons)
However, when compared to FFX, it's not so bad, and while I wouldn't call it outstanding, it was at least decent to above average, and I don't regret buying it.
As for the fanservice, I'll be blunt:
This complaint is pointless! If you took a good look at FFX, it had a lot of fanservice too, it's just FFX-2 decided to throw in a lot more, and I just considered it bonus eyecandy for those into that sort of thing, and I personally liked it not just because I'm male, but because it does look aesthetically pleasing to the eye as well.
In short, it was a good game.