My son has both. 2.0 is better, visually as well as the Toybox section.
In both versions the Disney Infinity software just gives you the Toybox, this lets you build a world – a bit like Minecraft. 2.0 seems to have more going on in the Toybox (I have never actually played it). If you actually want to play a game then you need a Playset piece, this unlocks one game. You then need characters to play in the game. The games are actually pretty good for kids, and seem to be a sort of story with lots of missions. The starter sets come with a Playset piece and characters. 1.0 has a better starter pack as it unlocks three games (Monsters Inc, Pirates of Caribbean and Incredibles) whereas 2.0 only has the Marvel game.
Yes you can buy the 1.0 characters and play with them in the 2.0 Toybox mode. I was in a Tesco’s the other day and they had lots of the 1.0 stuff about half price. From what I have seen the best part of Disney Infinity is the Playsets so if their is one your daughter really wants I would get the version that that works on. I am not sure if all platforms are the same, but on the Wii U once you own 1.0 you can download the software for 2.0, not sure how much it is, but cheaper than buying a new starter pack.
While it could be really expensive, my son seems pretty happy with a few bits for his birthday or Christmas and he has spent a lot of time playing on it.
