One difference in Mark Smiths course is that you take it approx. 1 month before the API test date so you can study and absorb the info from the course.
That could be good or bad depending on your personal situation and study habits.
It is less expensive than most other courses but you have to factor in a separate test trip to a test site so the total could be more depending on where a test site is from you.
If you fail, he offers a $200.00 price to retake the course if you went to ALL available classes.
If you take his course and go immediately to a shut down for 7/12's it might not be a good choice or if the test site is a few hundred miles away. Other than that it looks good.