If you want to connect anything via usb or use a class compliant interface there isn't much choice; this is it!
I tried a cheap generic usb adapter for the ipad which had patchy performance particularly with midi, it would work for a short period then just stop without warning. So I bit the bullet and purchased the official apple kit which is much more reliable (and should be considering the price), This will also charge your ipad during use, which is definitely a good thing.