[alanw]

I've never paddled a kayak with a rudder, but I think getting one would depend on how your boat tracks and if you do a lot of paddling in the wind.

Since I often go out in the afternoons when the wind picks up, I've occasionally had to paddle on only one side of my kayak for miles just to go in a semi-straight line because of strong wind, and I wish I had a rudder for those times. I'm not sure but I think a rudder may also be able to adjust your drift angle as well.