I play a 4 hybrid so it's wood-like. I used to carry a 5 wood but I hit it and my 3 hybrid about the same distance and the hybrid is a lot more consistent to hit.
My dad plays a 4/5 hybrid and a 6/7 iron that he just hits harder or softer depending on distance.
I have a buddy that plays a 7 wood and he says he pretty much only uses it if he hits a bad drive on a par 4 or a great drive on a par 5. He starts his irons at 6 though and also carries a 3 wood and an extra wedge.