I used a crypton once under the guidance of Man Father....nothing it could do that you couldn't do with a few bits of gunsons kit.
I dont miss the days of tappet adjustment, regular plug changes, fiddling with carbs, changing points, swapping condensers, dizzy caps and rotor arms, changing the air flow setting on the panel air filter from summer to winter, manualy adjusting drum brakes, setting timing, adjusting dwell yada yada yada
Pulling cylinder heads every few years for a decoke
I didn't mind those days, I was younger and you didn't have to worry about having to shell out hundreds of beer tokens for a little bit of electronic gubbins

On the other hand you had to deal with Distributor drives, burst diaphragms on carbs, difficult tappets although the Kent cross flow had easy enough ones to do with their self locking adjuster