GVT depends on it being followed the way it was originally designed. Trouble being, a few people do not understand or confused this with what GVT is not. You want 10 reps on every rep of every set. Not 8 &9 or 11 & 12. The goal is 100 rep's when done with the workout, nothing else. Use the same weight throughout this method. You do not add weight or lessen weight even if you think you should. Too much unneeded tweaking has ruined many productive BB'ing systems. Can start with 50%, 60% or what ever you body can handle based on a 1 rep max. The first couple of sets may seem too easy. No matter, press on with the same weight on the bar.
This form of training works best with the heavier compound exercises. For a lot of people, this style program is just too intense for direct arm work (curls & triceps) or other extension movements like lateral. But if that works for you, than great. But for most it will not be the best workout plan. GVT is not like 8X8, 5X5's and any of the other (which I like to call) square root workouts. Give any new training program a good 2 weeks to work into and than stay on it for another 4 to 6 week. You want to seem what the full potential can be for you so give it a fair chance.
Rest period can very but try keeping in the 90 second to 2 minute range for most exercises. For DL's , squats, cleans, C&J's, etc you may require at least 3 minutes between sets. That is being realistic. After awhile you should gain a certain level of stamina and require less time between the heavier compound exercises.
With GVT you do only one exercise per muscle group on that workout day. Though some will SS the chest (BP) with back (BB Rows) on a given training day (Arnold & Columbo come to mind). Also squats with leg curls as another example.You should not do any other form of lifting with GVT. Those one or two exercises (SS'ed) are the only ones done on that training day. Usually GVT is followed twice a week. But if once a week suits you, than so be it.
You joints are somewhat spared and you muscles should take the blunt of the training work load. Also the motor impulse units are greatly involved. One of the reasons that most will become so much stronger at the end of a GVT cycle (6-8 weeks). Olympic lifters had used this system in off season training. Some for the purpose of increasing the muscle bwt to a higher lifting weight class.
I cycle GVT during the year. Usually use dips, BB Hack squats, SldL's, Hi-pulls, etc as my compound movements. My best gains, by far, have been from using the bent arm pullover and press (DB's for me). Exceptional upper body training, at least for me. Cleans or Hi-pull are also right up there for me. Good Luck.