Top sheet chipping happens to every ski and has zero effect on performance. I could be wrong but I think the only reason it happens is because your skis are knocking together or your poles are hitting your skis. From my experience k2 makes very durable skis. I haven't tried atomic though.
I'd say the most durable ski is the line chronic, Ive got zero edge cracks, no delam, no base issues, and some minor chipping after two years of riding.