No, sometimes the stand looks full from a distance but if you walk up the steps there is usually a few spaces grouped together in random spaces. The spaces normally at each end of the stand though( if you get there not long before half 7). You may not be able to see 1st or 4th bend properly depending on which end you sit, but that makes it more exciting right? Especially if you can't see 4th bend!
Edit - I normally only sit down if my 11yo comes with me, as apparently 2 hours is way to long to stand for.