Well, mine's not attached to the coop since the coop is not done yet. I'm planning on using turnbuckles to attach them at the bottom. There's also going to be a connection at the chicken door, but I haven't messed with that yet. I'm planning to use either a ramp or a little fold-down landing that starts in the coop, and enters the run through a hole. Maybe I'll get to that tomorrow.
Mine measures 4x8 and is 5 feet tall. I do need to stoop a little, but I'm not planning on spending much time in there. Some kind of person-access was important to me, though.
this is a 10'x10' pvc pen, bird netting on top, my tractor is enclosed. So far, all is going well with 2 Light Brahmas, 3 Cochin and as yet an undetermined number of BCM that are pullets. Am putting shade cloth on the top as the summer heat has already started. Everything put together with zipties, light weight to move, has held up to our winds well.