I have the version for the IO-320 on my RV-9A. The light weight is good for the balance. The -9A has a lighter weight restriction on the nose wheel. It comes with the spacer and just bolts right up to the crank. No special or additional plates required.
I have had several chips taken out on the back side that I have had to repair with some epoxy and cabosil. Easy to fix, but it has happened more than I would have hoped for. The front side is still immaculate and the metal edge is in great shape.
Another issue that I had to fix was that the gel coat on the carbon fiber spinner bulkhead was rubbing on the rough inner surface of the spinner itself.
White powder is gel coat dust.
I fixed this by putting some thin UHMW tape segments on the edge of the spinner bulkhead. Hard to see in the picture below, since the tape is clear, but it has held up well and no more rubbing.
I've had the prop on and off several times (to fix a leaky crankshaft seal). The special Nord-Lock washers are good for a couple of cycles, but I did buy some replacements at the last go around and they aren't cheap. The prop adjustment is straightforward with the various width pins they provide. I've had it set to #4 and to #5 (current position). Not much difference in top speed. Performance is outstanding.