@1%
The preview options are now ok. and they work, just to find a fix with 10x since in practice, based on 5d2,
The preview is set to option so when 5X activates crop mode, the low rez but proper framing kicks in, but to confirm focus is sharp before starting record, 10x is used, cycle back to 5x, start recording.
The difference between 7D and 5d2 auto preview in Crop Mode are
7D
preview = proper 3x framing, low rez, acceptable refresh.
record = proper 3x framing, low rez, slow refresh
ADVANTAGE- framing can be "predicted" but not focus.
5D2
preview = proper 3x framing, low rez, acceptable refresh
record = canon 5x framing but grayscale, high rez, realtime refresh
ADVANTAGE - focus can be maintained but framing is difficult.
I don't know if the best of both cameras can be combined. I would be nice though.