Denise, I flew the symmetrical
spinnaker on my previous 23' san juan fairly often while single handing. I always did it without the
spinnaker pole (as that's too hard to manage in my opinion without help), and had no sock but relied on my tiller tamer at times. I only did it in light air with a fairly steady (ie. not shifty) breeze. It would make the difference between sailing at 2 knots or 3.5 knots to get me home again.
I have not used it yet on the 30 footer we bought last year, but would do so again in a very light, steady breeze using our autohelm, and given the extra boat size, even more caution.
Frank.