Did you come to any conclusions? I have a Navio 2 setup on a quad and just received a pixhawk 2.1 with Intel Edison board. I’ve not real plans to use the Edison because at this stage it’s beyond my abilities and time. I’ve not really heard of much implementable available add-ons for the Navio other than wifi broadcast. Edison seems to have a lot of development happening on it, would be interested in hearing of projects on either.
Also really interested in comparisons and results of Emlid’s reach rtk and pixhawk2/hex’s here+ rtk.