I agree about skipping Hammer. I've seen it here, the Hammer covers may not be the same as the Ebonite covers but there's a strong family resemblance. Oil absorbing covers like GB, Traxion, and Violent are going to be high maintenance, low lifespan covers. As you said, great reaction while it lasts.
You want a ball that lasts, get a Lanemasters. You don't want to spend a metric buttload of money on new stuff, get a Sure Strike. Or a Sting and Buzz for a combo.
SH