They have better accuracy and spin, at least the top Clevelands do. I've used the TM wedges for ages with great results and have only recently been able to get my first Cleveland and it's damn good. I've not yet had a holed approach but have hit many shots within a foot or so, way more often that with the TM wedges. You only need to use a tiny bit of backspin for most greens, full spin with decent balls will see the ball backing up several yards, care needed when the hole is close to the front edge of the green.
As soon as I get to the next level I'll add the 60° and in another 2 the 64° will follow.
Seriously good clubs.