Excellent question! I'm not really sure to be frank, but I kind of like the fact that I can do system calls (system(");, even though my linux knowledge is a disaster.
Means I can run python scripts and other linux commands.
PCIE on board for Wifi.
On board SD
Uno Campatible shields ( I use a lot of Grove hardware)
In hindsight, a better choice would probably be a Uno R3.
Would have been easier to make my Adafruit 2.8" touch screen work, though I now have cool libraries that give faster performance than i had initially.
GPIO performance suits my purposes, but probably not for other projects.
BIG CON- very little documentation, forum support for Galileo.
I take advice - what do you think about the Galileo, anyone?