If you have the money 750's are nice, but after using my new fm 1000 I would go that route.   You will never be limited on what you want to add in the future.  The 1000 also allows you to change fields and lines very easily compared to a 500 or 750.  If you start getting unlocks they stay with the monitor.   To switch steering ez steers are very simple.  I have cables in each of my tractors that I switch from and all you have to move is the display, antenna, T2 contol and steering motor.  It take me about 30 minutes total.  I don't know how long it takes to move and ez pilot, but here they are nicer than the ezsteer. 

  My experience is limited to Trimble, but they have been the leader in steering and corrections lately and I have had great luck with their products.  The rtx works great for me and as you may have read on this forum the x-fill is really nice for rtk users.   If you think you want to stay Trimble or move to another brand this is how I learn some of what I wanted to get started.  Go back 8-10 pages on this precision forum and read very thread that has the word or product Trimble (or whatever brand) in it.  You will learn all kinds of different things about displays and steering.  Also don't get discouraged by the negative as most of us only post when we have a problem.  Keep asking question here too.  Someone always chimes in.

Trimble may interface with your existing yield monitor.