I really like the poly bushings I'm running on my FLHTP. I did find though, that I had to re-tighten the bolts after about a year of hard use. No issues in the several years since that though.

Edit: Oops...I see now that you weren't really asking about poly, sorry.

 

I put poly in my 08 when I installed my 12". Honestly, it was kind of a bitch to do. They were hard and inflexible. I couldn't imagine how hard solid must be to install.

 

I have solid bushings on my 2022 RG CVO. I get a terrible vibration on the throttle side that kills my right hand on long rides. I have added the Rattle Killer under the throttle grip and also the grip puppies over the grips. Those two combined have solved/masked the issue.

I have installed 5 sets of bars over the years from 10 inch to 16 inch and never had this problem before with urethane bushings. I have a set of new urethane bushings in the shop that I plan to drop in when I get some time and see how it works out.