I'll try my best to answer these questions.
Their character designs are probably the best ever, for starters. There are about 12 types of characters: Tech Skylanders, Water, Flying, Fire, Psychic (or magic), Ground, etc. The only problem about this is that when you actually get all of them, and end the game, you get bored of it eventually. It happened to me, so that's why I had to abandon it because I can't play with anyone. -_-
The plot is actually pretty good, with plenty of quests and bosses. Its structure... very good compared to other games. There's no annoying pixelly graphics anywhere in the game, and the effects are great too.
But be prepared to face one con: you'll be spending a lot of money on this game if you're a serious player.