I should point out that with a carb and a MSD distributor my 512 had around 11 inches of vacuum. Now with the Sniper + Hyperspark combo I'm around 15 inches of vacuum at the same idle speed.

Digital tuning allows you to dial the combination in faster. Since it is easier to tune digitally it is easier to find the "correct" tune. Pulling a distributor out and changing springs, weights, and bushings gets old in a hurry. Opening up the laptop and changing the ignition curve digitally can be done while you're watching a football game and drinking a beer.