I have calculated the optimum shift points for the BMW M3 with a stock 3.2 liter engine and with a Conforti software upgrade.  The hp/torque data was taken from the Bonneville Motor Werks web site and 245/40ZR17 tires were assumed.  The green lines are the rear-wheel power curves (in kWatts/10) for each forward gear, assuming 15% drivetrain losses.  The cyan lines correspond to rear-wheel tractive force (in Newtons, again assuming 15% drivetrain losses) for each gear, while the yellow lines correspond to engine RPM.  As can be seen on the graph, the points where the power curves cross each other (equal power before and after the shift) also correspond to where the rear-wheel force curves cross each other (equal rear-wheel torque before and after the shift) and result in the best overall acceleration (neglecting flywheel/inertia effects).  If the rev limiter is set lower than the optimum shift points, then naturally one must shift at redline for best acceleration.  Please keep in mind that a different final drive ratio or tire size will shift the curves in the horizontal axis (shift point speed will be different), but the optimum shift point RPM will remain the same.

 Stock 3.2 M3:
The stock M3 powerband isn't well matched to the car's gearing.  It is too narrow for the relatively widely spaced gears and the rev limiter won't let you shift at the optimum shift points. You will feel a flat spot after every gear change.  At least it's easy to figure out when to shift: at redline.

Landsharked 3.2 M3:
This is a much nicer combination.  Jim Conforti's software really shines.  The powerband is now significantly wider and the revised rev limiter lets you shift at the best RPM or stay in a gear a little longer thru a curve.  The flat spots between gears are less pronounced, especially between 70-150 mph, were the power is virtually uninterrupted!  After 150mph, the engine runs out of steam as it approaches top speed of about 155-160 mph. Perhaps the car will go faster with a slightly taller final drive, but this would increase the 0-60 times.