If you count success as making it to but losing in the playoffs then the Habs have had way more success than the Leafs. If you judge the success of a team solely based on winning the Cup, then Montreal has sucked just as much as the Leafs in the last 21 years.
Lets not forget that the Leafs probably had the best team in 92/93 but if it were not for the infamous non-call... Toronto just may have gone on to win the Cup that year. Obviously we'll never know but who wouldn't have loved to see Toronto vs. Montreal in the final.