I grew up eating deviled egg sandwiches (I am 79) deviled eggs, hard boiled eggs plain
and have tried many recipes. The most memorable hard-boiled, and so-called deviled eggs, was eaten at a club meeting one day. They were so creamy and delicious, I asked the lady who brought them how she did it. She told me it was just a little mayo and French Tarragon.with a pinch of salt. I was never able to replicate the taste of hers, but at that time I was not buying farm fresh eggs. Maybe she also added a tad of mustard, but what kind? Anyway, I think with a good deviled egg, the simpler the better.