I have taken at least 3
handgun specific training classes. I did learn new techniques to try, some I still use, some went by the wayside after some trial and error.
Taking a handgun class IMHO is great for people who are
-relatively new to handguns
-want to work on fundamentals (important for all skill levels)
-Are looking to try new ideas or technical skills
-Enjoy shooting in a structured environment
Now if you want to hone skills and techniques you have learned in training classes, try shooing USPSA, IDPA, etc..
An 8 hour training class is not going to make you into an expert level shooter. And I doubt anyone here has the time and money to take a handgun class monthly.
You can easily shoot in a competition for a fraction of the cost of a training course.
Shooting USPSA for the past 18 months, I have vastly improved my skills in
-Accuracy
-Speed
-Reloads
-Malfunction clearing
-weapons handling
at speed
-Draw
-Sight picture
-weak hand only/ strong hand only
And I have enjoyed shooting in a friendly competitive environment.
I still plan on taking a training class for carbine and/or handgun yearly, but the use of both works best for me.
I encourage everyone to give both a try.