It can vary depending on the time of day I think. We've always been pretty lucky though. In the 4-5x we've used DME, I think the longest we've had to wait was 30mins. There were a few times, we got on and were on our way right after we got there, which was nice. Since we live on the West coast, normally our flights get in to Orlando about 4-5pm, unless we're doing a red-eye (we try to avoid those though!).