I'm sorry, but IMHO there is simply no debate - poor braking performance is intolerable on ANY vehicle that has the capacity to be ridden/driven at speed where better options are available.
That's complete bullshit Paul, that the drumbrake Laverdas are old and so should be ridden as if they were some sort of antique. An SF1 straight out of the factory in 1973 would easily hit 190kph and weighed 210kg dry. Are you going to try and tell me that in this day and age it should be ridden sedately because it has crap brakes? I rode my SF1 like i stole it and I HATED the drum front brake - and yes, it could have and nearly killed me for the gross imbalance between its considerable speed potential (in its day) and its ability to slow down. Sure, I rode 'around' the problem, but it didn't mean that's the way it had to be. As soon as I found a better alternative on my young man's limited budget, I leapt at it - a 4LS TZ Yamaha front drum. When I could afford it, i went to twin Brembos. Now it goes much faster and it has 4-spot R1 calipers, 320mm discs and a Brembo radial master cylinder, and it stops as quickly as its modern tyres will allow. And I feel a fuk of a lot safer for it.
I've said it before and I'll say it again - the factory didn't fit twin Brembo disc front ends to the SF2 because the Super Freni were just too damn good. FFS get a grip (the way a good 4-spot does!). Feel free to ride your SF as slowly and as leisurely as you like - and live with your drum brakes, but DON'T dictate to people who don't that their bikes are old and they should just accept the fact they came with a crap front brake.
Rant over.