I'd say a uni rig is faster. What isn't faster about it is all the screw ups to contend with when you're by yourself.

I'm not sure I'd want to do a really big event singlehanded with a spinnaker either. 20 boats can be alot to deal with, I can't imagine doing it with 50 more. That extra set of eyes goes a long ways into seeing traffic and potential issues, and the extra set of hands help in the "oh crap" moments.