I finally completed Pokemon Y (by completed I mean beat the Elite Four + Champion) and I have to say that it was quite enjoyable. I'm probably putting it up there on my list of favorite Pokemon titles.
My only gripe is that it was waaay too easy, this is probably due to the Exp. Share affecting your entire party. While this is quite handy and useful for training purposes, it severely cuts out some gametime. The way I used to play Pokemon in other games was each time I reached a new route, I would grind out 3-4 levels to prepare for the challenges ahead. With Y, I didn't have to do that AT ALL.
This is the party I completed the game with:
Luxray - LV 77
Scrafty - LV 80
Altaria - LV 96
Spiritomb - LV 74
Greninja - LV 71
Delphox - LV 79
As you can see, my party's levels are a bit unbalanced. Perhaps natures affect EXP gain somehow? I had 2 Lucky Eggs and all of them were traded for, so everyone of them had the boosted EXP bonus. Don't even ask me how Altaria got so high above the others, I only used it in about 5 battles total throughout the entire game, one of them being the Dragon Elite Four trainer. Spiritomb was rarely used as well, but when I had to use him it was quite handy to have. Scrafty and Luxray were probably the most used.
What I enjoyed most about Y was the story. That part at the very end where you battle that one particular trainer...I shed a few tears of joy for him afterwards. I have never got so emotionally invested in a Pokemon game before. /tips hat to Nintendo. Great jobs guys!
I broke down and bought Alpha Sapphire last night, currently in Rustboro City debating what Pokemon I want to add to my permanent team. So far I just have my starter (Torchic).