I don't understand all the headache.
If you want a seriously powerful laptop that will do what a full size machine will do, but is actually portable, and has an amazing screen with a resolution rivaling something over 20", then a Pro is what you want. It will be heavier, it will have a better screen, it will get less battery life, it will be a powerhouse. Fact.
If you want something decently powerful (extremely if I compare it to the first gen i3 in my 3 year old Windows laptop that gets 3 hours on battery) with something between 6-12 hours of battery life (be realistic, heavy work means it'll lose charge quicker), portability that can't be beat by anything other than a tablet, then get an Air. It will last longer when out and about, it will be lighter, it will get almost anything done that a Pro can do albeit slower, it will have a lesser quality screen. Fact.
If you just want to brag about having a Pro Retina when an Air is all you really need in a laptop, you'll justify it to yourself one way or another, rendering this whole thread moot. Fact.
Seems pretty simple to me. If you want something to replace your beast of an iMac, this shouldn't be a difficult decision.