my experience with CDI-better fuel efficiency and the engine is smoother..maintenance free contact point as it is used only for pulse signal for the CDI.
I use the TAC ignition kit from Maplins. Points don't get pitted as the current is all handled by the TAC module, so points last till the heel wears down too much. The module also filters out any points bounce at high revs. Not bad for £14 and an hours soldering building the thing.
No difference to fuel ecconomy, but scope shows a better HT voltage at the plugs.