i wouldn't rope drop 7DMT unless you are at the front of the rope drop line - you can get a lot else done in that time. i would try to ride it during deluxe resort late hours (if you have) or just buy the lightning lanes - this isn't RotR, you'll be able to get them. it's probably worth a ride if you don't come often but i wouldn't wait hours for it (or anything).
It's a decision factor. If you rope drop 7DMT, it's still a good 30-45min wait. In that time you could easily knock out Peter Pan, Winnie the Pooh, it's a small world, and another ride. Peter Pan especially can back up quite a bit. But, if you're set on it during a busy season, it's still better than a multi hour wait.