For important cases, my crontabs live in a file under versin control. Then I just I replace it with 'crontab crontab-for-this'.
AFAIK the edit option existed in 4.3 BSD (first time I used cron) but for some reason I opted using file under my home directory. Could be that the default editor was vi (or ed) and using emacs was much easier.
But yes, for odd jobs in random computers I just kick crontab -e.
@nixCraft