I know that I am an oddity around here but I strongly prefer symmetrical chutes for single-handing. Assymmetricals are harder to safely jibe and are way too easy to get wrapped badly around the forestay and as a single-hander you don't have the necessary crew to get them cleared. I have a similar problem with sock launching a spinacker single-handed since you don't have the crew to clear an hour glass and sock launching is more prone to getting an hourglass.
In a general sense, assymmetric spinackers work best on high performance boats and on fractionally rigged boats, which rarely head dead downwind and where there are big VMG gains made by reaching. Symmetrical chutes work best on heavier displacement boats, and boats with masthead rigs where there is less loss to heading dead downwind.
Anyway, that said spinakers of any type are really helpful for any time of boat when sailing at deep angles and greatly increase the number of available sailing days. I am a very big fan of Quantum sails when it comes to spinackers. They seem to have a real advantage in terms of stable flying shape.