I used butt connectors in one situation ONLY. Emergencies. Going up to the roof to replace a bad node...i'd crimp the node on the ground with the butt connectors, fly up on roof with wire strippers and make the cuts and recrimp...ended up in the end I had WAY too many bad nodes to deal with this way and introduced other issues...so I've since pulled all those bad nodes down, replaced with new string, and just use pigtails with soldered connections and shrink tubing on it. If I had a portable soldering iron I would never resort to the butt connectors...I've also just stripped wires, marr connected them and then electrical tape, but that wasn't very effective.