I am writing this on what is the best laptop I've ever owned.
The combination of battery life, quality and power is a huge step forward.
My previous laptop was a 2007 MacBook Pro - now carrying out home server duties.
I stopped using it around 2009/10 because the battery started swelling up and was never replaced due to cost vs benefit.
Instead of getting a new laptop, I held off as my iMac and iPhone were taking care of my computing needs fine. The iPad 2 was my first re-entry into the mobile computing world beyond a smartphone.
For a long time, I tried to adapt the work I needed to do on a mobile computer to the iPad platform. I went through the iPad 2 and then onto the iPad 3. I took them to Taiwan and Europe and used the camera connector kit to backup and view my photos from my SLR. I took them to class to take notes in lectures. I took them to work to take notes and keep organised.
What I learned was that the full size iPads (9.7 inch models), were not made for people like me. It doesn't hurt to have one - it never does - but if I could have only taken one of either a OS X device or an iOS device for my non smartphone needs, for me, it would have been a difficult choice.
Computing on a MacBook is now insanely great.
The new line of Retina MacBook Pros and MacBook Airs released in 2013 with the Haswell 4th generation processors makes choosing between a MacBook vs an iPad a much fairer choice.
The iPads no longer have the trump cards of size/weight and battery life. Haswell has made that a much more even playing field. Add on the power saving improvements in OS X 10.9 Mavericks…and the battery life on these MacBooks is now truly "all day". 10 hours on the 13-inch Retina Pro and 13+ hours on the 13-inch Air.
To be fair, the iPads have caught up on their shortcomings too. The iPad Air and Retina Mini are now fairly beast-y when it comes down to computing power.
The comparison can now pretty much be solely made on the preferred operating system as the gap between everything else has been finally closed to a point where they are small trade-offs rather than deal breakers.