I had the fuel tank of my Honda S90 Sports powder coated back in 1999, along with the frame, fork shrouds, chain guard etc. It came up as quite to quite a good finish and with a bit of polishing didn't look too bad, however, the tank has large chrome steel panels on it so that there was never a huge amount of the powder coating actually visible.
The finish you get from powder coating varies with the business doing the job, some are very good and others are average, it is just a case of finding the good ones.
CJ