Andy,
Most sessions I've seen convert fairly cleanly from NTSC to PAL - one
BIG gotcha is to make sure your monitors are set up properly in both NTSC
and PAL. The lack of pedestal in PAL makes a dramatic change in the look if
the monitor doesn't compensate. Remember that black is black - whether it is
7.5 in NTSC or 0 in PAL the monitor should look the same.
Rich Torpey