I purchased a 64 GB WiFi only iPad 4 about a month ago to replace my “old” iPad 1. Both of my iPads are black and at first glance one would hardly see the difference. There is a positive difference in functionality though and I’ll just mention my impressions and not get into much technical detail.
First of all, the “Retina” display on the iPad 4 is AMAZING – just as good as magazine printed text and sometimes better.
Also now I can now keep more apps in memory (without restart) because the iPad 4 has 4 GB of RAM whereas the iPad 1 had only 256 MB. Then of course there es the processor speed: faster on the iPad 4 and definitely noticeable, however I am not sure how much the extra zippyness is due to the A6X processor and how much to the additional RAM (does it matter?). Both iPads are powerful enough to run video with no problem so the primary speed advantage to me is in browsing the web with the Chrome browser.
Then there is the weight – the iPad 4 feels (and is) lighter. I find now that I use the iPad 4 even more than before (which was considerable) and am starting to even do some actual work on the iPad whereas before I treated it strictly as a consumer device.
Finally, there are the camera’s (front and back). The iPad 1 didn’t have this and I really like having it.
I think the Apple supplied “cover” is both cheesy and over priced. Below is the case I purchased from Amazon.com for about $16.