With storm bags, they are built tough. But, the ball cups some times tend to wear out or have sharp edges that can scratch your ball.
The good thing about storm is their customer service. I had ordered ball cups to replace the ones in my four ball bag and 3 ball bag (separate occasions) without charge.
Also, as far as the wheel bearings, I have bearings from my RC hobby and used them for the wheels on these bags. I change them out when they start getting loud.
And with KR making majority of the bags now for most companies, just pick any design or color. I'm liking the KR bags right now over Storm.