So we all have similar thoughts pretty much. I tend to get pressured into a CF workout here and there based on people I know so when I do get around to it I always end up destroyed in some form or another obviously my shoulder being one but it's the other joints that get hit, the burn out feeling, and for me the feeling like shit part after the workout doesn't go away for at least an hour or slightly longer not the 10 or 15 minutes and walk away deal.
Before when I first jumped on CF, I could recover quickly and adapt pretty well though strength was pitiful. But now, my recovery sucks. Last summer it required separate sessions usually and I made good gains through intervals and running and that transfered pretty well to any metcon I did as long as it was paced.
So perhaps it's true, a returning X-fitter or more advanced trainee likely needs sport specific training or programming to make their gains consistent and not wear out. Unless of course they have the aid of say drugs or are that very genetically gifted few.
Anyways, fire away guys, interesting stuff to ponder on, obviously this forum has pondered on that a million times though