Yep, I've made them more times than I can count. They are not difficult, but time consuming,
Definitely worth the trouble. You've all got to try them.
I find chopping the dark chocolate for the shortbread crust the most tedious. When I'm in a hurry I grate it, though it's better chopped.
The nice thing about these is that they can be made in stages, and they can be made many days ahead.
They're always a hit. When you bite into them it's an explosion of flavors. I love to watch people's eyes while they chew their first one. Also, because they are so rich, they don't disappear quite as fast as some sweets. One or two is enough for most people.