Yeah......wasn't aware of the McGuff system, but could see a Art Jones influence in all this. Mentzer, to a lesser degree. Did a search for more information.
Just my personal views, no big deal: Similar protocols, over the years, with this type effort. Rememberingng that muscle respond better to fast contraction, than slower contractions. Sort of like a sprinter (muscular size in the calves/thighs) as opposed to longer distance runners (leaner musclur size in calves/thighs). Seems also, with this type program, more attention to stamina rather than a forecful muscle contraction at the end. Like a semi-static hold during a full ROM. Static holds can be extremely important in any type training, where very heavy weights are concerned. I didn't come across any long range studies/personal experiences (3-6 monhts to a year) of results obtained by subjects. Sure they are recorded out there, somewhere.
(Art Jones had a well know bicep workout, where a negative chin (curl grip) was included with a BB curl. The negative chin was 60 seconds to it's conclusion. Excessive TUT and one cycle only (of course)).
Any system is worth a shot, so if dj181, or anone else, would like to test it out..that would be great. Maybe 3 exercise to get started with this program rather than 5, as a breaking in period. Seems it may be quite demanding on the CNS at first. Can't say if it would be a worthwhile training ststem, with regards to max size and strength...but than again, don't know until you try.
If reaching a sticking point. which most of us do, than your not getting enough rest time between workouts (you body's response is not catching up to the demands placed on it..usually based on the CNS). Either allow more time between workout days or take a week, or so, off from training. The common cause of a sticking point is too many exercises, too many training days or going to the point of failure too many times every workout. Poor diet/quality of food, another factor. The mental factor, like the same old, same old workout, enter into here also. Good Luck.