I have a 11in MacBook Air/iPhone 5S combo and couldn't be happier with my rMini. As others have mentioned, owning the iPad Air and 11"/ 13" MacBook Air/Pro would have seemed to close in size.
About a week ago I was in the market for a MacBook Air to complete my ecosystem, and at that time I had both the Air and rMini. Only because of the redundancy in size I decided to trade out the Air for the MacBook Air. The rMini is my go to device when I'm mobile or want quick consumption, with my Macbook being the device I use when I want to perform tasks that can be done on the iPad, but not as seamless as a full fledge computer. Usually I pull out my MacBook Air to do whatever is needed and I'm right back to my rMini.