Again, a lot of this is theoretical. Coverstocks have improved . . but is it noticeable or relevant? If anything, they're simply designed for synthetic lanes now. Wood was higher friction, and was the predominant surface 15-20 years ago, but now that the majority of houses out there have synthetics, it requires a "more aggressive" ball to get the same reaction you'd have on wood. I see no noticeable effect on hook or ball durability, and again, this is from a public state of view, obviously I've never seen balls hook like the Endless Nightmare before, but as far as visual ball motion, it doesn't look much different than the now years old Virtual Gravity, which really didn't look that much different from the Super Charge, which didn't look that different from the Trauma ER . . see where I'm going here? Now, a lot of this does have to do with lane maintenance and oil volume increase. I have a feeling a brand new Trauma ER wouldn't look anything close to an Endless on today's conditions, but again, I don't think ball technology has really advanced persay, it's just adapted. Ball durability is a big thing with me, and it almost seems to be getting worse. It's only natural, given physics and the rules therein, but things like the NRG coverstock from Storm doesn't seem to make a difference, but theoretically it sounds great.