Hmmmm...only 45 minutes to set up by Denny?

It used to be as I recall a lot longer, he has an unbelievable amount of aids.
Training aids have a place in golf, it is just that most fail to use them for their intended purpose or fail to use them correctly IMO.
I once was a big time believer in Video. Then after watching and reading all the different analysis that is made on these, I have come to the following conclusions:
a. Many do analysis with regard to positions not alignments.
b. 2 Dimensional analysis can lead to faulty conclusions.
c. Camera alignment/position is critical to getting an accurate understanding of what is actually going on.
d. It is difficult to identify using video power applied and how it is being performed.
e. The camera can't define feel which should be in the intended consequences of the mechanics.
As noted in the original post, training aids need to compliment the golfers stroke, not just as a swinging or hitting but in loading, etc.
Training aids in the correct hand are great demonstration tools provided the user knows the aid.
I think most golfers who have a camera, could spend about $20 and have a complete practice workstation that would by far out weight any training aid. Couple that with some accurate information and they should be well on their way to at least IDENTIFYING faults and potential causes of faults. For those without camera, a mirror will go a long way in assisting the golfer. The best is to have a Knowledgeable person assisting in monitoring.
Nothing beats a 3 dimensional view of the golf stroke in question.