My neddy has had NB shoes for ages now. They're £65 a set and he is shod anywhere between 6 and 8 weeks depending on wear and tear and hoof growth.
NB shoes are regular shoes. The metal is slightly different to other shoes which enables my farrier to bang them about a bit to fit my neddies hoof wall shape. He isnt changing the natural break over point, he places the shoe to my horses foot shape.
When he was first shod in these shoes (after we'd taken off the huge dinner plate, toe clipped monstrocity) he placed them a bit further back to support his heels, gradually using smaller shoes until the hoof wall was strong and the correct shape and size. It took around 2 years to get his feet right.
I have heard of Cyteks, many of the horses i know were shod with them up until 2/3 years ago. Cytek made the shoes heavier and changed their shape and they seemed to loose their popularity with horses, their owners and farriers alike.
My farrier does occasionally shoe a horse with rear clips but usually to help the hoof wall stay intact on a foot that has been badly shod previously.
I had a horse on livery with a terrible over reach problem and was always cutting his front heels but with his first NB shoeing he was soooo much better.
Hope this helps.