PO85-RD is AWESOME as a final polishing/jeweling step. It is a diminishing compound and will clean off extremely faint swirls and micro-marring. It's great for a "maintenance" type compound. I.e. doing a light re-polish every 8-12 months to get rid of minor swirls and clear coat damage a car accumulates over the course of a year.
On a first time correction job you'd want to use it AFTER something a bit more aggressive like the PO91E or PO83Q.
The finish after hitting my black car with PO85RD is so nice that it literally almost pains me to apply sealant and wax over the top of it.