I can say from personal experience BIG!

Here is a picture of the first servos I ever used. They had an advantage when used for a pull-pull system. Before you jump to any conclusions I was 13 and I built them from an obsolete Heathkit kit with a 2 stick 3 channel radio. They are Kraft KPS-9 servos in case any of you wet behind the ears pups don't recognize them.