If you're talking about the current Blue Hammer ..

It is one of the very few urethanes that I have kept. Even the stock 4000 grit surface gets very good, easy length; it has a better backend than most urethanes, old and new, on today's drier conditions. It has hitting power on light hits, that is closer to true resin than any other urethane in my recent experience (except for the SuperNatural which I found very over/under on most conditions).

It is the easiest ball I have thrown, with true strike potential on every shot, to throw down and in on the driest of true oil patterns, except, of course, true fried lanes where you even have to play the 3rd and 4th arrow with plastic.

That said, it is still very susceptible to carrydown.
Oh, and it is not for a wet/dry condition, unless you have a lot of hand or a lot of surface (1000 grit or lower). You do need a blended oil pattern.

If you have a lower rev rate, I'd suggest drilling it strong (not more than 4" pin-PAP) because the max differential is only .032 or thereabouts. I'd start with the stock 4000 grit surface and roughen it, as needs be to get the reaction you need.

All this urethane talk has me wanting to punch up my Booyah.

Just throwing in my two cents, I like the Pitch Black better than the Newer Blue Hammer. I had two Blue Hammers, while the ball was good. The Pitch Black hits harder and stays in play for more games for me. Used the PB on CHeetah and Wolf in the summer and average 213 on cheetah and 205 on Wolf with it. Again, just my two cents...

A teammate has one and likes it for its hitting power, but he has more initial axis tilt than I do. However, it goes into a roll like NOW!!, about 5 feet past the arrows, unless he finds a lot of head oil to skid it through to the midlane. He has to be real careful where nd when he hits the dry; it is very sensitive for a strong urethane.

I might buy it

I bought a Blue Hammer a year ago to replace my Natural.  Primarily a spare ball, but I have had good luck with it on some THS and short tournament patterns.  One note I think is important.  When patterns get to the point that you have to move in and go away from the pocket any urethane loses its effectiveness from a carry standpoint.  Therefore I don't really use them much when patterns force me inside.  They are very good when I can square up outside against the oil line, and will allow me to stay there for awhile. 

I like the Blue Hammer better than my old Natural because of the core 

I used the black urethane through the 80's, love it.
I purchase the new black urethane in October, love it.  Still has the smooth finish in the back especially in drier conditions.  Although I'd still like a little more drive through the end.

Totally bone dry, I've had minor issue with the blue lately. I need some heads for my style and/or cover adjustment. I like this ball much better than other "modern" urethane I've owned in the past. it's def. a keeper for me.