The main thing really is the light port, I charge my 5 and mini with the same charger so the older 30pin cable will be a little issue.
But the size is really it for me, I like the mini and it's cool but for mostly reading kindle ebooks and pdf the size is just better.
Also want one of these.
http://www.booqbags.com/us/folios/booqpad/BPD3-GRG
I wish they made these for lefties...
Call me crazy, but from the looks of it you can just turn it 'upside down' and the writing pad will be on the left. You can slide the pad out and reinsert it at the top.