Looking at its user manual, the Airbox is nothing anywhere near the other two. It is just a box which runs the Memory Map UK VFR charts, so it's basically useless for outside the UK, and for £1500 I would expect a whole lot more than that.
If you just want to run MM on a large screen, with minimal in-flight interactivity, you can pick up a new or used Motion LS800 on Ebay, which (being windoze) will run anything and everything.