GVT Training or 10 x 10 / 8 x 8 -- Good Routine For Me?

Folks,
 
First time poster and new to the boards. I'm 40, 6-2, 208 and looking to gain lean muscle mass and burn that annoying fat that just doesn't want to leave certain areas.
 
I've been working out pretty consistently for years, but I've been stuck for a while. Starting mid-January, I decided to give a new type of routine a whirl. I believe the technical term is "German Volume Training." It also goes by the name "Ten Sets Of Ten." Another version is Vince Gironda's 8 x 8 training. Anyway, the idea is this: You do many more sets than usual at lighter weight to "recruit muscle fibers you normally wouldn't" with less sets. Also, there is very little rest between sets -- say 15 - 30 seconds. This also has you out of the gym in no more than 45 minutes. You could Google this and someone else probably explains it better.
 
Here's a typical chest / back routine:
 
* 8 x 8 bench
* 8 x 8 incline DBs
* 8 x 8 seated rows
* 8 x 8 DB rows
* Mop Up: Dips 8 x (until I can't do 8)
* Mop Up: Pull Ups (which I sometimes do in between sets)
 
The creators of this routine recommend only one exercise per muscle group...I break this rule clearly.
 
Anyways, I've been doing my version of this and it is KICKING MY BUTT! Like I said, I've been working out for years and this just devastates me.
 
I've been doing it a month, and I feel like it's working -- I've more or less gone from 202 to 208 and my midsection is tighter.
 
One other key to this workout routine: For the first time in my life, I started to get serious about legs. Until mid-January, I never gave a damn. Figured it was a waste of time. Now I'm doing squats, deadlifts, lunges, etc.
 
Anyways, I'm curious if anyone has used this type of routine before with results they can speak of. Also, I'm concerned about the idea of "overtraining" as well.
 
Any and all comments welcome.
Thanks in advance.
 
KY