What reputation? Maybe it's because I started on mountain bikes and that's what I learned to work on, but I've been riding more than 30 years as an adult, and I've never heard cantis were hard to adjust OR to work on. I have them on three bikes, and I don't even think about them.
Speaking specifically of Atlantises, I built mine four years ago with some low-end cantilevers I got from Rivendell (I can't even remember if they're Shimanos or DiaCompes, only that they cost $28), and I haven't touched them since the first day. They must have at least 8,000 miles on them. If I had to judge, I'd say they work AT LEAST as well as the 105 sidepulls on my Rambouillet, probably because they have Matthauser pads and the 105s are stock Shimano.