The only Commando I have ridden was an early 750. It seemed to be quick enough. One of my friends won a production race with a Commando 850, but I don't think it increased sales. Very few Norton twins were sold in Australia from the 1950s until the mid 70s. I only ever bought my 850 motor, because with the Seeley frame, the bike would resemble a Gus Kuhn racer. I never believed in the 850 motor, so I did not race it until I moved to Benalla, where the race circuit is closer to home and the hospitals. It turned out that I was completely wrong about the motor - with methanol fuel, it is excellent- better than any 1960s Triumph motor. I think the reason we raced mainly Triumphs before the two-strokes arrived - we could not afford a Manx, and there were plenty of secondhand Triumph parts.
I think with the K2F magnetos - as they got older the varnish and capacitors inside them failed. Even when they were reconditioned, they seemed to fail. I still have one which works, under my bench. The SR magnetos last forever and are cheap. Also, the capacitor is external and easily replaced, and the coil is held in by two screws - easy to carry a spare.
With the K2F, if I remember correctly - they fail when they get hot. Getting a bike to a race meeting is too much work for that kind of stupidity to happen. I think I experienced it twice. I would have ridden at race meetings ten times without a problem, with the Lucas SR.
It is a time in my life which I would rather forget.