I have the same hammock and am about the same size. I too have had my feet slip out several times a night but once I find the 'sweet spot' it sleeps very comfortable to me. If anything this hammock is a little too big and has lots of extra material on the sides. The pitch you hang your slings at has a lot to do with it too. But for the price think the GTUL is a great hang.
I much prefer the small Grand Trunk Nano and take it on all camping trips and use the Ultralight for dayhikes, naps. Goodluck!