The Suzuki 850GS (1981) I have been working on in exchange for the bags and trunk now on my V is nearly ready now. (Needs rear tire and some minor tweaking) Tested the charging system the other day with a digital voltmeter...
BATTERY (key off) 12.7 volts
BATTERY (key ON) 12.2 volts
IDLE (1200 rpm) 12.9 volts
2500 RPM 13.2 volts
4500 RPM 13.6 volts
It does spike a little as the throttle is blipped but the R/R does a MUCH better job of holding the output voltage in basically the same spot regardless of engine speed or load. (Using the brakes, high beam, turn signals etc has only a momentary drop and then it goes right back...