I just applied for a job that gives a date range for completing jobs and I thought it felt so civilized, lol.  It got me thinking about features I like from some MSCs and dislike from others.
With Coyle I like that I can choose a date (obviously within restrictions like no Saturday, etc.) I get a little irked when I click on others and see lots of grayed out dates.
I love when any email shows the payment, oh and location, for the job upfront.  I hate clicking, scrolling and reading only to find out it's $8 and one location in Utah.
I love the ability to change a date on my own.  CXG makes this pretty easy.  
As for a wishlist, one thing I would love would be able to search a particular date.  Say I'm going to be in a particular area on Thursday, it would be so awesome to see jobs available on that date.