On my CD28 there is standing headroom everywhere, I'm 5'11" , I do have to duck under a beam going into the head. I know it's not the 27, but the 28s are pretty cheap from time to time, and they are nice boats that can circle the world.
I should add that when I have stood in my boat (I've only had it a couple months), it's with shoes on and the sole has a rug, so I may not have to duck while barefoot and/or without that rug.