They do what they say they do = infinite camber and caster adjustment to any position within the circle of the strut top. You can set them up to your heart's desire basically. I went to the suspension shop and provided my desired setup specs and they adjusted them to suit. DOUGMO (George) in this forum also has a set for his track car and highly recommends their adjustability, especially for caster as it doesnt move the position of the wheel in the wheel arch.
I recently purchased a new set of BC coilovers with their own pillow ball camber tops plus I already have 3.5' lower caster mounts installed in my car for added caster. I therefore probably wont need the K-Mac's due to being overkill for a mostly driven street car. My set are the Kmac Stage 3 full race version with pillowball top (all silver).
Pros: Unlimited castor/camber adjustability. Great for setting up your front suspension to suit different race tracks. Quick and easy. Look great B)
Cons: Several pieces to each camber top. They are a bit fiddly to setup at first but once in place you can easily loosen the nuts and move the top to whatever position you require for camber/caster. Like all camber tops, after a few adjustments, evidence of knocking them into position can be seen due to alloy/anodising wear.
See pics: