I'm importing avchd as optimized media, editing the optimized media (rather than proxy media) then exporting the file. After export, when I pull up the info box for the exported file, under codecs it says
"Apple ProRes 422 (Proxy), Linear PCM, Timecode." Is this normal? I thought I was exporting straight ProRes 422. I've never used optimized media, and I double-checked preferences to make sure it was not checked. I have got "better performance" checked in preferences, do I have to change it to "high quality"? What up with this?

Edit: Never mind. Somehow the output settings got set to proxy, though I've never used it.

There is a good key "gotcha" on this though.
For those who used FCP legacy there was an option to output in Sequence Codec.
FCPX doesn't have that so even if you're editing optimized ProRes you still need to set the Export codec... as you've discovered.