Now, I'm mainly casual, but usually, I crank out a good, long post, trying to get in some character development, because my characters need that. Like, if its a hgh school RP; my character walks out an entirely different person, because of the influences. If she/he becomes comfy with drug addicts, she likely becomes a chain-smoker, etc.

In Advanced, however, since there's 4000+ characters almost every post, it might take a while to get out some posts, with some character development easily showing. So, if you expect posts every 30 mins, they're either going to be short...or a whole HP chapter, pretty much. With the amount of characters, there's going to be a lot of reading, so that will slow it down.

You should either expect the minimum, or the maximum. The middle takes a long time to get, and since most people post the middle, it might take a while. Simply because, you need to be much more descriptive, and so it will take much longer. Usually, there are amazing writers in Advanced, so there's going to be the maximum a lot, because they can get it down wonderfully. 

If its going slow, the middle will start to show, and since people might get more lazy when it gets slow, or maybe they need to chat with their friends in the same scene, and try to get a response that is accurate to how their character is at the moment.

I mean, I don't mess with Advanced, so I don't know.