The iPad Air is Apple's fifth generation iPad and the true successor to the iPad 3, whereas the iPad 4 was mostly a speed bump and lacked the fanfare associated with most of Apple's product launches. It also marks the first real redesign of the tablet's form factor to some extent. The iPad Air is significantly thinner than the previous iPad, noticeably lighter, and it sports a reduced bezel that more closely resembles that of the iPad mini. It's such a drastic change in feel that Apple chose to add the "Air" moniker to this iPad. It seems Apple always chooses a standout feature to rally behind -- upgraded cameras, high-resolution (Retina) display, Siri -- and this time around it's the physical dimensions garnering all the attention, though the iPad Air offers excellent performance as well...
Any major computer upgrade generally requires a full software reinstall too. No so if you heed the advice in the guide to Upgrading a Motherboard without Reinstalling. PCSTATS Tips