I've had my bug up to about 185-190 kph (2.0 914 engine) with stock 4 speed. My engine was screaming at 5800 rpm.
If we had no speed limits here, it would have been nice to shift into 5th gear and cruise at that speed.
Alot of people go for the 5 speed so they can have 4 really close gears for racing and shift into 5th to cruise on the highway at 80 mph.
You can build a 4 speed with 3 close ratio gears and 4th would be the tall gear for cruising.
If you are just driving on the street with some highway use, use the 4 speed and get a 3.875 R/P.
If you are road racing, get a 5 speed with proper gearing.
Have you ever played Gran turismo 3 on playstation ? Its amazing how fast you can get a car going by playing around with the gearing.
Wow .. that was a broken up post now that I read it again
Sandeep