Wago is a top quality provider. What makes their splices and terminals so nice is the size range of wire that can be used and be held tightly in the same mechanism. The ones in the OP post will splice 12 gauge wire with 28 gauge and everything in between. That is a fairly big wire and a REALLY TINY wire. Most splices have much, much narrower range.
One thing that I feel the need to say is that wire nuts have no place in pinball machines. Ever.