It is hard to decide, we have both. The good quality runners lay lots of white eggs with a blue/green tint and have a very upright carriage. The cayugas eat alot, lay about 1/2 the eggs as runners but the eggs they do lay are like araucana blue, and dont make people laugh when they see them. Will you just have them to have them, or will you eat the eggs or extra birds? If you want dual purpose, go cayuga if you want egg layers that come in many colors, go with runners. Metzers waterfowl in CA has runners in 4 colors or so that show decent.