When I make pesto, I usually borrow a food processor and blend away.
Last night I used manual labor -- lots and lots of manual labor -- to make pesto.
The difference was stunning.
It was like the difference between gourmet whole grain mustard and French's.
Nothing wrong with French's mustard, but damn, when you've partaken of pure pesto ecstasy, it's going to be hard to go back.
If you (1) like pesto (2) have never used a mortar and pestle to make pesto and (3) you want forearms like Popeye, then you owe yourself the experience.