I run the RV200 whirlwind prop on my 9A, and collected a whole series of rock chips and dings before it was time to send it in for the hub check at 752 hours and 5 years of service. I elected to have WW tear down the blades and refinish them, new nickel leading edges, new paint etc as well as the hub inspection - pretty much a worst-case scenario for the blades, though the hub was in excellent shape. This was March of 2021, total bill was $3425.