I have a PBG3S 250 w/ 160m ram, running 8.5.1 and QT4.0 has been running quite beautifully. Since I also have an "Mpegcam" (made by Hitachi) which produces MPEG1 video files, I have been viewing these w/ 4.0 and I think compared to 3.0, the picture quality is slightly better. The color seems more vibrant somehow and picture seems a bit more detailed. Also, previously I have a lot of problem trying to edit these MPEG1 clips with QT Pro3.0, but w/ 4.0 Pro I've had limited success. I can edit the video files most of the time (and great to have the start/end tab!) even though the resulting file is still very large (apparently if you combine bits from separate MPEG1 files, you end up having a file that is as large as the sum total of the 2 originals!). One odd problem I've been having with both 3.0 and 4.0 is that sometimes if I view the Menace trailer (not the new, "better quality" one), afterwards when I open one of the MPEG1 videos I've shot would not play properly when it's double-sized or full-screen. Only way to solve that is to restart the system then I can view the same video (or any other for that matter) any size I want with pretty good quality. Any one have an explanation for this? I've been struggling to find a way to edit these MPEG1 video for a long time and am hoping that maybe Final Cut Pro will do the trick...