Thanks Jim. I already have the Kirk equivalent of the RRS setup (3232 + Kirk adapter + Kirk QRC). I primarily shoot action field sports with this setup. I have been thinking about a tripod setup with the smaller Kirk ballhead + Sidekick for my 300mm f/2.8 and non sports shooting.
I am thinking that the smaller ballhead with Sidekick is good for the larger lenses but without the Sidekick I can use a smaller more manageable ballhead on my lighter shooting setups. Do you think this is good thinking or should I be thinking about larger ballhead right from the get-go? I have almost no tripod/ballhead experience.