I've really enjoyed the coils I bought from Dyna, I swear the bike starts more easily on my 71' CB500, but it could be placebo and I just have her dialed in properly. As for the Dyna S, many have bad things to say about it, and then point people to the Pamco ignitions. http://4into1.com/pamco-electronic-ignition-honda-cb500-cb550-cb750/
I for one, Love my electronic ignition on some of my other bikes, so I do believe it's a good call. With that said, points aren't too bad once you know how to adjust them properly. Usually You can get them close with a small 12V light setup, enough get the bike fired up and then get a timing light on it afterwards to verify you did it right. When you do it with the light, make sure you rotate the engine a few times to check that you have it opening right at the "F" mark (NOT THE T!!!!) for the 1:4 and 2:3 sides of the plate. And before you do any of that, make sure your advancer unit is working!!