Yeah, its worth it if you can get it for a good price.
Its also a good opportunity to go through and hardwire your vespa. All that superfluous wiring where you can't ride with a burned tail light is just problems waiting to happen. Nothing worse than riding through a puddle and having to suss out electrical gremlins by a street lamp and a lighter at 2:30 a.m.
I saw a modest performance gain all around, but I bought the whole kinetic engine and decided to see what the difference between the vespa and the kinetic engine performance wise. It is faster all the way through and gave me an extra 3mph according to my speedo.
I doubt that is all from the cdi, but more likely from different porting in the kinetic case.