I will probably use the Air 2 more than the Pro. The Pro by itself felt big, light and brittle (opinion - not fact). I put the Pro in a Logitech Lighted Keyboard/Case and now I like it. I love the MacBook Pro 15" & 17" lighted keyboards and think the unlighted Apple keyboard would not have worked for me.
My wife, who loves her iPad 3, Air & Mini surprised me by saying she loved the Pro (but will probably not buy one). We are 71/70, retired and iPads are a convenience (not work).
What I really want is a mouse (I don't care what Apple thinks about it). Without a true file system (not cloud & internet dependent) I still will stick to the MacBook Pros & Windows 10 for real computers.
I think the Air 2 & Pro are apples & oranges. If you need it, the Pro screen size wins hands down. If you are going to carry it a lot the Air 2 may be better. Seen together, the differences should make a choice relatively easy.
I will be using the Pro to create Excel spreadsheets but the Air 2 to just read and perhaps modify those spreadsheets. Even the Pro seems handicapped with Word & Excel (or Pages & Numbers).
I'm writing this on a Mac mini with 27" LED display. Its all about what works for our needs, age and capabilities.
Jerry