Well I think cyclex has an optical system. I think a couple here have bought it but I have not heard about the performance, though Ken says it is pretty good.
I've got it, I like it, it smoothed out the idle and I can idle lower than before, I haven't had any misfires. I haven't run it long though, so I can't say how it holds up long term.
I did have an issue with coil mounting, the coil is not similar to the stocker and a little hard to mount. Ken shows a bke with the coil mounted under the sidecover, to me tht is too far away to mount it. I (and others) have mounted them where the stock coil is, with the plug connector facing either front or rear. Do not mount it to the side, mine rubbed on the gas tank and possible shorted out.
One good thing about the Cycle X system is that it has 4 timing curves, with a few switches you can select what you want.