what size steering wheel do most people use?

i ran a 300mm but it seemed abit big,

just purchased a 270mm SPA one but that seems small, not tried it yet though

is there a "normal" size people are using?

I ran a 320mm wheel on my last Indy which seemed fine to me

I drove a caterham recently with their standard wheel (which is 260mm I think) it felt ridiculously small to me, required huge amounts of effort to turn at low speeds and IMHO makes the car less easy to control precisely than with a sensibly sized wheel

That might be just me though