To answer the *actual* post: no, I haven't found it on recent flights. I do know that foam might compress over time. I'm sure it does on every airline. Certainly if you point it out to an f/a and ask them to write it up it will, or may, get replaced. I'm sure that CO monitors these things and if there's a systemic - read "more than just your flight," or opinion - they'll eventually do something. Likely not fast enough for any of us.

Or, you could just post nasty stuff on flyertalk about CO (or UA) which seems to be all the rage now.