I have tried royal conpound once on my 811 c/t. I think I put on top of 4000 grit. The ball started earlier than I wanted and hit too soft for my liking. Granted, this is on old worn wood lanes. I changed the grit to 3000-4000 sanded, and the ball seems to react better. I use the royal polish or whatever it is on my primal rage all the time and I love it. For me, there is a huge difference in the polish and compound

FYI Use of ROyal Compound or Rough Buff is best used at 2 underlying grits. 500 grit + RC will take a ball to the 3000 - 4000, depending on amount and time spent on the spinner and pressure applied.
1000 grit + RC or RB will result in a 5000 grit polished appearance.
Any higher grit than 1000 (maybe 1500) will not result in a higher resultant grit level than 5000, as near as I can tell.

RC (or RB) is not a polish but an abrasive compound that makes the underlying grit finer and finer. Once you get to 5000 grit, more or less, you will achieve a shined or polish appearance, the same as if you started with 1500 or 2000 grit and applied a good polish.