Hey Stefan, I definitely agree that it would be an interesting topic. I've toyed with the idea of using specter over the years. I haven't yet found a use for it, but I know that many people find it to be an essential tool in their belt.
it seems to be a perfect fit for arbitrarily nested data structures, like if you're taking a big blob of data from one external source and lightly transforming it before sending it elsewhere
I echo Michiel's sentiment about cleverness, I've even been able to make things in plain Clojure that are too clever for 2-months-later me. Heh.
I would love to hear about your experiences (or anyone else in here). Where has specter (or spectacles) helped you in a substantial way?