I tried flying my symmetrical solo a few times. The wind was below 5 kts and I was on a downwind coarse. It made a huge difference in boat speed. I do have a tiller pilot and a sock. The advantage of the spin over the genoa or jib is the lighter material will fill and obtain it's desired shape much easier. W/o the sock I am just not able to do it solo yet. Maybe more practice I will be able to, but I am not inclined to try at this time.
Also, it is just fun flying the chute. In my book that is worth the effort.