Until recently I would've said "go Pro" if you're anything more than a web searcher/emailer. But work requisitioned a 13" Air to me for travelling. I have a 15" Pro as well (OK I have 2, one personal and one through work). All are Retina.
When my current Pro gives up the ghost I'll be going for an Air as its replacement. I used to do a fair bit of video editing, but the only remotely processor-intensive thing I do now is running Parallels. But with the RAM maxed out and a decent amount of SSM I experience no difference. I do still keep a USB 3 bus powered 1TB hard drive handy; but haven't needed to use it once so far.
My road warrior gear is now: MacBook Air 13", iPad mini (with keyboard case) and iPhone 6+.