I've taken my Vandal (60x5x35 I believe) down to 3k at a tournament a few weeks ago as I needed an option to both grip + make the corner on fresh and wasn't happy in practice with my other pin up options.

The Vandal is a special ball to me as it gets through the fronts with ease and has a smooth, yet strong move off the back (think Hyroad on steroids) but by sanding it, the Vandal read the midlane real hard (which was fine at the tournament) but lost its distinct pop off the back.  I have since returned it to rough buff polish and am once again happy with my ball reaction.

Has anyone polished up or sanded a Vandal? If so how did it work and how does this new cover take to surface changes?

I have not, I have bowled with mine with the factory finish, first DV8 ball for me and overwhelmed by it's performance. I needed a ball for a very poor league house condition, I needed length and this ball gives me length, and then is where mayhem breaks out, this ball makes a great hook transition to roll which is angular but very controllable and hits and carries beyond my expectations. Have sold others based on my performance with this ball. The DV8 Vandal will be a large complement to most bowlers game