The Procede controls the meth valves and controls the engine settings needed to get the maximum gains from the meth. So, you need both. In previous posts Shiv has recommended but not required that any flash tunes be removed. It depend on how aggressive the tune is. When I spoke to him he felt the Dinan tune was conservative enough to be ok, but wanted to do some data logging after installation to make adjustments. The people that have had it installed so far have removed their flash tunes.
The gains posted so far have been relative to the mods already on those cars. I don't think anyone has posted dynos from a stock car, but I would expect similar gains.
2010 E92 M3 LeMans Blue on Bamboo, Black Chrome, MB Grills, Gills & Vents, MB 220, GP Thunder, LUX AE, Dinan Racing Exhuast, Dinan Intake, Dinan Tune, Dinan 3.62