Oh yeah, killer vid! Underrated NO DOUBT!! These old RF Power Series amps were crazy priced back in the day. This "300 watt" amp was $999 in 1990, which is equivalent to around $1800 now (in 2017 dollars).
Another fun fact, the Rockford Power series prior to 1994 were all four channel amps. (mid 80's to early 90's) Models included:
Power 100HD (15x4 at 4 ohms or 25x4 at 2 ohms or 50x2 at 4 ohms)
Power 300 Mosfet (50x4 at 4 ohms or 75x4 at 2 ohms or 150x2 at 4 ohms)
Power 650 Mosfet (125x4 at 4 ohms or 162.5x4 at 2 ohms or 325x2 at 4 ohms)
Power 1000 Mosfet (150x4 at 4 ohms or 250x4 at 2 ohms or 500x2 at 4 ohms)
Da trick? All were rated RMS power at 12 volts from 20-20,000Hz with less than 0.1% THD
-BigD