To answer your question: lack of A6, lack of LED FLASH, no panorama mode, no built in gps for the wifi model...and of course, the retina screen. But those things I have on my iphone 5.
Do I wish for those on my ipad mini? hell yes, but if apple don't deliver it, I can't help it. I'm not going to buy anything else because there is nothing out there that has this complete package of the mini (biggest component, user experience and apps/airplay/facetime, entire apple ecosystem)
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It's whatever is out right now - I'm not gonna stand by and wait an eternity for the best of the best because you know apple will never create the perfect device..if they did, there will be no incentive for the next iWhatever!