we used a 3 position cylinder on our 2011 robot to control the rotation of the arm that held tubes. it gave us one angle for the middle pegs and a different angle for the high pegs.
we used 2 double acting solenoids with the pressure port of one of them blocked. i don't remember how we plumbed them, but i assume it was like the Bimba schematic shows.
The one drawback, as noted above, is that you just have 3 positions - fully closed, fully open, and one intermediate step. So with a 4+6, you would have 0, 4" and 10" extensions. you cannot do a 6" extension.
This is the inventor version of the robot, but you can see the cylinders.
http://www.chiefdelphi.com/media/photos/36564