For those interested in playing along at home, a nice, hard-working person who can't spell has created a comprehensive page of all the CI Top Ten performances to date. They say they'll update it regularly, which remains to be seen, but if you're curious about the kind of stuff CI2 is dishing out relative to AI3 (or any of the AI shows really), I recommend checking out any of Jacob or Kalan's performances, especially the ones from Top 10 week. Theresa's Good Mother from that week is also worth seeing, though her subsequent two performances were disappointing -- she just doesn't seem to know how to pick the right songs.
And if you want to laugh until your sides hurt, check out Shane's take on The Darkness, which is made much, much funnier by the awareness that up until this point in the competition he was a competent but dull singer of syrupy ballads. The falsetto has to be heard to be believed. I personally got a huge kick out of it, though the Scary Faces make it a difficult performance to watch more than once.
P.S. If the above links don't work, try here, but remember to right-click and save, please.
P.P.S. The aforementioned props were in Jacob's "Space Oddity", which is certainly one of the most gobsmackingly bizarre things I've ever seen in my life. Yes, including Bowie in his heyday doing the same song.