The Wago you are showing is a 773 series. I've never used them, but I've heard good things about them. I use both the Wago 221 lever nuts and traditional wire nuts and have no issues with the 221's. I seen some testing where they hold their own up to 40 amps which is double their rating. The convenience factor and easier when troubleshooting are big pluses. Wire nuts give you a greater surface area contact when done properly and are cheaper. When it comes to pre twisting I always pre twist with 12 gauge and 14 gauge I find it to be optional. Btw, wire nuts are not just a cap, they are to tightened with significant effort, but not overdone, and are part of the joint, hence the metal cone inside.
We use the clip on Wago and never had a problem. We never use the push-in type tried them once and found they were not suitable for our work. But the clip-on’s are great. Try them I think you will agree. Regular wire nuts also can loosen. Back in the day we soldered the connection and friction tape it they never came loose. Some say the solder would melt and brake the connection I doubt that would happen since if it did you would have a lot more issues than solder going on.
For a DIY person or at home install I 100% agree, for an apprentice Electrician we won’t be using those new stab in ones for awhile because of overall cost.
