The human realy can't see more than 24 fps, or better our brain can proces more then 24/27 fps. In game you can have more, in this way if some frame are lost or unprocessed you will not see any difference. All video are made with no more then 25 fps, if you upload any video on youtube is processed at this frame rate (flv, avi,xvid, mpeg). there's some special video recorder with milion frame per seconds like "super slowmo" but at the end will show at same frame for human seeing. Google for "subliminal" and you can find something interesting about some frame adict to a video and the result.
Anyway ghosts are bad coded and change fps will result in more lag, like fov that will f**ck up scope..