It seems to me that this brand (
http://www.ignitech.cz/en/) of ignitions systems has never been mentioned here as a feasible option.
I've recently installed one of their product on my racer CB750 and I'm absolutely amazed.
At 1/3 of the cost of a Dyna programmable unit (at least in Europe), they are able to supply a FULLY PROGRAMMABLE system, easy to install and to use.
It's really amazing, I was almost crying of joy for the results: the engine run way smoothly, and with a different sound as well!
Carburation is more stable and I don't have to fiddle with it all the time with every weather change. I'm not even using it at full capacity, as it can receive input from TPS, fast shifting system, commanding exhaust valves, and much more!
Here a pic of the ignition graph I'm currently using:
What's your maximum advance for a tuned 750 engine? At the moment I'm at 44°, as you can see, but I'm thinking to give it a couple of degrees more...