Ever since the essentia tubes were changed in 4.1, I found Thaumcraft automated essentia distillation incredibly finicky. When it works it's very efficient and beautiful, but I can't count the number of times I had to rebuild my distillation setup because the essentia just refused to flow for no apparent reason even though the build was exactly the same as before and I just had to interrupt the material supply for a few minutes because I was working on my Logistics Pipes system. Rebuild it the same way or the other, knowing all the rules, made no difference. Sometimes it worked, sometimes it didn't. Incredibly frustrating.
As a result, I tend to avoid anything that requires a constant essentia supply. It's a shame, really, because I love the style of how Thaumcraft 4 does things.