I have been using several Samsung SyncMaster 191r Plus 19" monitors for many years. I run them in DVI mode at 75hz (on my Mac Pro i am offered 60hz and 75hz) because i have a visual problem that makes me nauseated when using monitors at a refresh rate below 70hz. Yes, this is in DVI not VGA. There are many people with the same problem, but for most of us 60hz is not a problem. But for those of us who have this problem, which is at yet un-named but i would call "monitor sea sickness", we can tell the difference between a 60hz and 70hz refresh on DVI. Therefore there must be some difference in how the monitor handles the signals.