This is not a side line. I deal with pinion angle "in the real world" on a daily basis.

In addition to constantly answering phone calls and E-mails on the subject (including customers of chassis/drivetrain shops), I set pinion angle on everything from street cars, to drag cars to circle track cars to lifted 4 x 4 trucks. Once, I even corrected the pinion angle on a hydraulic low rider.

The only thing these vehicles have in common is that ideally, under operating conditions, the front U-joint should run as close to parallel (parallel, not necessarily "pointing" at each other) with the rear U-joint as possible.

Once again, regardless of the method used to get there, this is how 2 joint driveshafts are designed to run. I'm more concerned with the relationship between the transmission and the pinion, than the angle of the U-joints, as this varies with ride-height/power-train height.

BTW, if the driveshaft angle is so severe it binds the U-joints, I adjust the slope of the transmission to flatten the bend. This is not usually necessary except for vehicles such as short wheel base lifted 4 x 4s.