Concur about the GoPro footage.
plays smooth as butter once imported to CC.
in CS 6 it had a helluva time keeping up without a render.
normally once the import/conform is finished (and do let it finish before cutting)
and you save, it should not need to again, unless it’s moved to another
storage volume.
I hope they fix that in CC eventually…it should never need to re conform
footage once it’s been done the first time.