Thomas,
From what I saw of the Black Pure Hammer, it was as much resin as urethane and I only saw it with the stock surface, very polished. Like resin, the more polish you applied, the longer it went and the more it hooked at the backend. The Burgundy Pure Hammer was pure resin and was more for medium-light to medium oil, for me.
From what I have seen of the new Blue Hammer, it goes longer than the AMF Hype and the Naturals but not as long as the Desperado and the Avalanche. I have only seen them dull (P4000 grit, the stock surface) but they seem to hook more than any other urethane with a decent backend and better drive than any except the Avalanche and the Desperado. It's behavior remains urethane-like. While I've seen good drive I;ve also seen them leave 7-10s when the midlane is too dry and they can't retain energy. They're for short oil, not dry conditions, UNLESS you have a lot of ball speed or less than average revs.
"None are so blind as those who will not see."