There is only one caveat, your stern pulpit must have a lower/second rail. I have found there is a kit (although I cant remember the manufacturer) to use as a substitute which bolts on between stanchions. As I recall this kit does not look to be as clean of an install.
I replied to this over on Anything Sailing, same answer, wouldn't put them on my boat. The stern corners are my favorite place to sit while sailing so I can see the telltales on the headsail, these seats would eliminate that space. Of course, I don't have a modern big assed boat, it's an offshore boat with a fairly small cockpit. I would also worry about someone sitting up that high while heeled over, or in rough conditions. They would be great at anchor though.
I can sit in the seat and steer my boat with my foot and a line attached to the tiller (Light winds when things happen slowly or under power ) On my boat it actually makes more room in the cockpit for us.
Our Catalina 36 came with them. They are a must have on any boat. Great place to sit and if you have any guests that are prone to getting sea sick, these seat prevent it. It keep them up high with lots of wind on the face and view on the horizon.