I have to say, with the Rev n Nator + Firecore distributor, my car runs much better compared to the MP performance Electronic ignition conversion kit. Its on a 440-6. I did happen to get their coil too. I purchased the distributor separately. At the time, they did not offer the pkg with distributor. I just got the coil and ECU.
The Rev unit is basically for those who wishes to have the stock look. If that is not your desire, then by all means, get the full MSD or other system.