I absolutely loved the Last Story. I picked it up at the same time as Xenoblade on someone's recommendation and, after starting both, I was significantly more hooked by the Last Story and finished it before revisiting Xenoblade. To be honest, I still haven't finished Xenoblade, so I can't really compare the two other than what I've already said about first impressions. I really do need to get back to Xenoblade but it has been shunted down my list a little by Tales, among other things.

I agree with what you've said about the main love story in the Last Story - totally cringe-worthy. I liked a lot of the other characters though, the customisation was awesome and I spent a lot of time running around like a loser doing every sidequest I could get my hands on, which was a lot of fun. Some of the quests that involved stealth glitched out on me, making it a bit hit and miss as to whether I could complete them, but even with that I found the variety of the types of quests I faced to be pretty excellent. The battle system was also pretty neat, with pausing midfight to use abilities was a cool addition; I'm a big fan of combat that involves less button pressing and more strategy.

But all 'round I loved this game and obviously something about it appealed to me more than Xenoblade did. Once I get far enough through Xenoblade to determine what that 'something' is, I will let you know.