I can see your point. In this case I think of Deisel. After all of the times he topped, I was excited when I saw that he was finally going to bottom. When I watched that episode, it was pretty clear that it would be the first, and definitely the last, time that he would bottom. After that, I didn't care if I saw him bottom again or not. Of course, it helped that he didn't get hard as a rock and shoot like a howitzer. Once a model does that, no matter how much I like to see them top, I always see them as versatile. I guess my advice to models would be, "If you want to be known strictly as a top, don't get hard and stay hard while you're getting fucked".