Me, I just had my sidecar powder coated. I would not recommend it over paint, myself. If you muck up one area with pc, your not going to be able to just touch it up so easily. PC is durable, but not indestructable. The cost of doing my front, rear and sidecar fenders, plus gas tank and hack was right at $600 bucks down here. The pc shows every single ding, dent and wave in the structure. Some of the dents I got were not from me, but from the pc guys using a stand to do the sandblasting and flipping the hack over and hitting a post on the stand. Only one local pc guy could handle the hack size and I went through 4 different pc guys in trying to find someone who could do a decent job. If you ever have your rig at a campsite, be aware that DEET spray can cause spots on pc that won't come out and eat away at the coating. Careful where you spray your bug spray. To me, paint is cheaper and easier to apply or touch up in the long run. Wish I had gone that route instead of the pc I chose, but that is just hindsight, now. I didn't coat the frame, as it didn't look bad enough to pull it all apart and do. Unfortunately, my home is a leased home and the garage is not setup to allow for paint, as the water heater is out there and the landlord would not allow it anyway. I went with the pc, but for as nice as it may seem to someone else, I'd opt for paint in any future jobs. It all depends upon what you are expecting from paint and the colors you choose, but for durability and ease of touch up, I really feel the paint is the best option, myself.
If your going to have the hack done up in pc, be sure to get the sand blasting done with someone who won't warp anything. Also, once the sand blasting is done, you can repair any small dents and dings with JB Weld, but you have to work fast with the stuff, as it really, really hardens quick if you don't do the sanding in a hurry. JB Weld will stick in the heating process, but Bondo will drop out and can't be used for a pc project. Believe me, any dent or ding that is not repaired prior to pc will show like a sore thumb afterwards. The pc guys are not likely to treat your tub as if it were your baby, either. Be careful in who you settle with and always, always, always do a good inspection of the parts before you accept them. I had to have two fenders completely reshot, as they missed a lot. I wish I had inspected the hack body much closer, as there are dents there that can't be popped out after the pc is applied, as it will break or crack the coating, now.
Good luck in what you choose. Random photos of Dog Taxi in pc.