Bumper choices

What is the general consensus? I have good O.E.M. urethane bumpers. Are they worth sanding, cleaning up to reuse/paint? Will individual retainers work with them, or use the o.e.m. style?  Are body workers better at painting o.e.m. or the flex fit ones. I know they take different type paint base. Can the o.e.m. ones be media blasted, or will they deteriorate? No judging or show car. Just a driver. I'm open to suggestions, or advice from experience.Thanks! Preciate it. 

I repainted my '73 in '86 w/ lacquer and just scuff sanded the bumper cover and used a flex agent in the paint.  Since it was a daily driver for about 20 years, I'm sure that all the sun exposure contributed to the urethane becoming very brittle and it started breaking off in pieces when it was about 35 years old.  I considered getting one of the "flex" fiberglass covers but they all said that they req'd some trimming to fit properly.  I purchased an OEM cover from my dealer and will install it when I get the car painted again.