Nothing but problems with the al3. I had a brand new one out of the box go bad. I had to carry a spare and it too was bad out of the box. If you have to update, I would seriously look to move to the Digital stuff.
Alot depends on how much boost you are going to run. If this is a race engine and going to make more than 12 lbs of boost, then you might consider an MSD 8 or even a MAG. This is what MSD told me when is was messing with blower motors.