I have a new MBP that I use (15") and want a light backup device. Something with a dedicated keyboard, ability to use Excel or spreadsheet, Word or basic editor, and view plans and annotate them (with a pen, if possible or otherwise a good touchpad easy to use). Touchscreen no necessary, but a tablet with a pen would be good, but need a good secure keyboard (not bluetooth and the lack of security with that). What's the ideal device? Something to throw in the bag with the MBP and be able to take, or for times when I don't need the MBP in the evening, something that will let me do everything without the main computer. Something I know a MBA might be (light, thin, good battery, Mac OSX). But maybe a non Apple device? I'm steering toward Chomebook Pro or Surface or Tablet with S Pen (but probem with BT keyboard with that one) or a Tablet S Pro. What you think is good? What you use as your backup for your MBP?