I use the ladder style roosts. They all use the highest one, which is right above the top of the window, and the rooster is closest to it.
Thanks for the info. We're looking at all kinds of coops and getting ideas from this thread about what chickens like instead of just getting a "pretty" coop. We're too old to build ourselves. In calling around different coop companies many of the representatives were not aware about perch placement - that it should be slightly higher than the nestboxes and that the flat side should be facing up and not the narrow side. I haven't found one company yet that builds the perch with the flat side up.