i have been on one of these courses. it was the best thing i have ever done. DG - driving a car requires common sense, but you need a drivers licence....anyway.
i won an award for best newcomer for 2011 candidates, which appeared in the local, and then regional papers gaining me an incredible amount of both domestic and commercial work.
as said already, you meet some good guys, and as someone new to window cleaning (4 years only), i was surprised at just how many tips/tricks i picked up. the chaps that run the corses are very knowledgable, and take the time to answer all your queries. regardless of what i have read on here in the past. the chaps at impact 43 will bend backwards to help you both in and outside of the class rooms that they use.
i would recommend to anybody.