I recently had an old steel Peugeot powdercoated black. The finish is great, but this week my bike fell over against one of my other bikes and hit its chainring (no chain). Now the top tube has a big scratch down to the metal. I also noticed that the coat itself was very thin, like the guy who did the job wanted to save on powder or something. Will try to post pics if it's any help. I was so pi**ed off, but hey my stupid mistake, because i dropped it myself.
But isn't powdercoat supposed to be 'bombproof'? I know if you try hard enough you can damage anything, but the bike just toppled over slowly and unfortunately hit the sharp teeth of the chainring.
So much for the powdercoat myth then...