I haven't used that specific model, but it wll make an improvement over stock. I've used the MSD 6AL-2 and Crane cd ignitions on my race cars. If I'm not mistaken, the 6A model (p/n 6200) doesn't have rev control and the spark energy is a little lower than that of the 6AL-2, but still much better than stock because it will spark multiple times throughout 20* of crank rotation.
You should get better throttle response, slightly more power especially at higher rpms, and faster starts. Mileage may improve slightly since combustion will be more complete with the cd multiple spark discharge.
If it were me, I'd spend about another $50 and get a new MSD coil also. You'll get a lot more voltage than the stock coil puts out.