I have to agree with you on the main storyline, it's too easy. Especially if you decide to check out the Coliseum, then you'll be overleveled for the rest of the game. But the game can still screw you over, since about half of attacks that only enemies can use besides the normal Attack command deal fixed damage. One of the potential reasons the game feels so easy is because I *think* the difficulty of the main storyline is tailored so that it is a bit too hard for someone who just skips all the sidequests and does nothing but follow Active Links. Problem is that someone who actually does all the sidequests will instead just have a cakewalk.

The one point I don't agree on is that there are no challenging fights in FFX-2. That's where the Via Infinito comes in. Said dungeon is, in my opinion, the hardest dungeon ever in a Final Fantasy game. Chac on Level 80 will totally destroy you unless you're really, really prepared for him (I fought him with 3 maxed Mascots, all Level 99 and still needed 4 tries to defeat him). And from then on, it's chaos. Dark Elemental can take you out in one turn if it decides to use Ultima and you're not healed completely, the combination of Elder Drake with a spellcasting monster is deadly because Elder Drake gets like 10 turns every time the spellcaster casts a spell with a relatively long animation. Lacertas can be really problematic because they deal fixed damage (1/8 of your max HP if you have Protect) and are the fastest monsters in the game. Overall, the fights were just too difficult and I had to run from more than half of them to escape Game Overs. The only sad part about the Via Infinito is that the final boss, Trema, is insultingly easy if you managed to survive the horrors you had to face up till then.

Unfortunately, FFX-2's Battle System has some flaws that can be abused to hell. Prime example: Cat Nip in the non-International versions. Breaks just about every battle in the game. And people don't feel bad for abusing it. Why? Because the battles are too damn hard without it. Another flaw would be stagger-locking Chac so it can never get a turn. And so forth.