It is, indeed, an OverEZ. I bought it used off Craigslist, so I don't know if it's considered a medium or a large. It's a little over 6 feet long and just shy of 4 feet wide, not counting the nest boxes.
I really like the coop. It's incredibly sturdy (pretty heavy, too; it took four people to unload off the trailer). I like being able to open and close the windows. But, the previous owners attached what looks like old wire refrigerator shelves over the outside to prevent raccoons from getting in. Since my worst predators are mink, we also fortified the windows with hardware cloth.
There really isn't anything I don't like about it. It's the only coop I have where I don't have to open the coop to access the nest boxes.
I am currently underusing it. There's only a Wyandotte and a pair of Cochin Bantams in it this winter. But, when I get my Buckeyes this spring, I am hoping to move out the current residents. I think, since they will also get outside to run about, I could put five, possibly six, standard-sized girls in there.
Good luck putting it together.