I had mine coated on my '05. Big mistake for me! I don't know if it was the coater or the soft aluminum rims but take as much care as I could, used rim protectors, etc. every time I changed tires the coating would crack and eventually flake. Also it didn't stay as shiny as advertised.
For me, the main reason was to match the bike color. It is a three step process to get the right color match. (Chrome, color then clear coat.) I almost stopped at the chrome undercoat.. It looked pretty darn good. I did the work myself.
A secondary benefit is, the rims are a breeze to clean.
I did mine to make it easier to clean. A quick blast of Lemon Pledge and they wipe clean quickly.
I would guess that flaking comes from a mistake when they were done whether they failed to clean and prep properly, didnt coat the wheel enough, or baked properly. I use a local company that specializes in it and has been around forever. I had them do my 1500 wheels a long time ago and later my 1800 wheels. I had mine done in Silver with a metal flake and they have held up well.
I don't remember if it was my Valkyrie or Wing, but one of them did not have clear coat on the wheels - maybe both. The coater has to be a good one. I had a set coated and it was horrible as stated above and cracked and peeled. I got another set of wheels and had them coated by a bigger, more reputable company and did not have the same issues.
I wish Honda would have never clear coated the wheels. Small scratches and dings are very apparent. not to mention the clear coat peeling. Almost impossible to change the tire without nicking the rim.
I actually used to take pride in my polished wheels.I had them looking almost like chrome and after the initial cleaning, they were easy to keep up with.
Most I know powder coat for the look of a custom color or ease of keeping their wheels clean which only requires washing the wheels and not having to mess with metal polish. I personally like the look of polished aluminum, but it comes at the price of spending a lot more time on my wheels. Not a big deal here in Ohio; mother nature gives me from December to March to do it, so there's ample time...