Yeah. I used my uncle's original iPad and it defintely stutters on iOS 5.
My iPad 2 was perfect on iOS 5 and 6.
The mini will be a nice speed upgrade for you.
Stop making me wish it was Friday already...
I think at this point I'm going to have to work from home Friday morning so I'm here to sign for it. No shipping info is making it so I can't presign for the package :/