Brian,
For me it's not important at all, because I have no commitments on Monday. The biggest arguments I hear on "other" forums when the topic of Saturday/Sunday comps come up are those folks who have religious commitments on Sunday and those that have jobs on Monday and want to be home on Sunday and rest; some say say it is easier to take off work on a Friday than it is on a Monday.
This year the American Royal changed to a Saturday/Sunday comp and it still filled to 505 teams....so I guess if you build it they will come.