I've never used either one but I have a Magpul SGA stock on order. I've read that the hand angle/placement feels better, and the cheek height can be adjusted for bead, ghost rings, or optics. I also like the variety of sllng mount options.
I've heard you can punch yourself in the nose shooting with the Hogue short stock if you cheek it wrong. Can't do that with the Magpul due to the different grip design. Still, the Magpul looks ugly and the Hogue more traditional. I might try out the Hogue if I dislike the Magpul.