I agree with Jim about the use of tac-tic. I currently have the elbow one and have ordered the wrist version. They are pretty simple training devices, but IMO, simple is the way to go. I have more training devices than ole Tin Cup could store in his RV. I used to think that was the way to go before I recently discovered TGM.
One thing I discovered about training devices is that they don't in themselves fix anything. You can't expect to start working with something and all the sudden wake up with an incredible swing. The "generic" type swing aids just have never helped me.
I have found they are only useful if you are working on 1 particular thing, like having a flat left wrist. Then they can provide useful feedback during your practise sessions. I think the simpler to use the better...
The tac-tic elbow is great for working on making sure you have extensor action. I have always had a problem with my left arm breaking down at the top of the backswing. When I first got the elbow tac-tic it would click if this happened. The only problem is it is very difficult to "will yourself" to keep your left arm straight. Once I discovered TGM and extensor action it has become much easier to keep my left arm straight by not focusing on it, but instead focus on the right arm. By applying PP1 and using the visual from the book that the right arm wants to straighten (extensor action) it applies the necessary pressure to keep my left arm straight at the top, through impact and all the way to the follow through.
I think by using the dowels with the impact bag, and using the tac-tic wrist thing at the range, I will be able to make equal process with having the long sought after FLW....