They are great.
The natural backspin will stop the ball perfectly on full shots from the fairway and even punch shots.
The added backspin comes in handy when playing from the rough - the thicker the rough, the more added backspin. Similarly when playing from sand.
These wedges also change the short game. Added backspin will not exactly stop a pitch or chip shot cold - that would be rather contrary to physics - but it will definitely help control the rollout. This requires some adjustments to Iconian's famous guide to the short game. With full backspin, pitches and chips from the fairway or light rough will play very close to their stated distances, whereas in Iconian's original guide (based on (shall we say?) obsolete clubs), you need to subtract a few yards of strength for a pitch shot from the fairway with backspin.