I recently completed a combined EMT-B/AEMT class for the first time and I felt like it was really easy. The people running the class kept stressing that it was a high level, fast paced, advanced class that is easy to burn out of and easy to fail. But in the 5 months that it took, I felt more than prepared to take the NREMT. I finished the class with a test average of 93% and finished the NREMT-B exam in around 30 minutes near the minimum number of questions. The AEMT exam isn't adaptive yet, so I can't guess how well I did but all of the questions took around 55 minutes to answer. That being said, there were a few people in the class that had a more difficult time with the material and one dropped out about 80% through the course.
Also, I didn't realize this thread was almost a month old, apologies.