Your strength seems to be sky-rocketing.  Which makes  sense, since you are basically training in the "strength & power"  range.  I might try your style of clustering, it certainly looks to be  very effective at strength gains.
Whats your advice regarding how to program the volume for these cluster sets, and when to increase the loads?
		
		
	 
Well first off, not only am I the strongest I've ever been, I'm also  the biggest I've ever been. My upper arms are now sitting pretty at  17.5, which I'm pretty happy with, although I'm also (paradoxically)  disappointed because I know the majority of that is biceps increase and I  need to find more work for triceps. Forearms are the biggest they've  been, legs are back up to where they were when I was training them more  regularly but I'm most happy with the back development (all over) and  upper traps.
Regarding how the clusters and max-stim work:
-If I can do 5 reps with it the upper load, it's generally time to bump.
-Somewhere  in the 8-15 rep range per exercise, depending on the load (closer to  2-3RM, vs closer to 5RM) and whether it's the first exercise hitting  that body part.
-I bump the upper load during a workout if I can do the 4th rep of the cluster comfortably.
-Obviously there's a bit of intuition involved for loads.
-Rest  periods are 3 minutes as a minimum, realistically. You know, 3-4mins.  Frankly, I'd be surprised if anyone could do 3RM clusters a minute or  two apart.
-Failure is not a part of my training philosophy; all going back to the CNS.
-Form  is important. You don't dick around with near-max compounds. And when  you forget/get ahead of yourself, you break a rib ... oh no, wait, that  was me 
 
-Max-stim: hard to say exactly what load to use. You'll  find you can probably do 15 or so max-stim reps with an M-time of  around 30s or so at your 3-5RM (probably varies a bit depending on the  exercise, technique and relative strength). If you start spacing that  M-time out longer, the workout takes a bit longer but you're going to  get stronger and bigger as well. I don't think 1RM is what you want to  be using for max-stim. But up to 3RM ish-range is fine. 5RM is also  fine, and there's no reason it would work 'less well', except you'll  probably need a few more reps to achieve the same results. If we were to  graph progression over an extended period of time, you'll progress  faster if you expose yourself to higher loads sooner rather than later.
-EAT.  But, having said that, if you're cutting, I still find this style of  lifting to work well. You aren't inducing intense energy needs during  the work-out and you can stretch rest times a little if you're tired.  Caffeine is also awesome, obviously. I've had to go off it for a while  for medical reasons, which sucks, but I'm doing fine w/creatine all the  same.
-Courtesy of Totez, I dropped deads to once in every three  upper sessions. They're CNS heavy and I need/prefer extra time to  recover.
I use load as the mechanism for inducing stimulus  for hypertrophy. Obviously any successful program factors this in, but  many trainees will use extra volume as a mechanism for inducing  hypertrophy before/rather than progressing the load. My decision to do  this is partially based on preserving the CNS. I find volume to be a  greater inhibitor of recovery than load is. Additionally, and just as  importantly, it's well established that progressive load (an increase in  threshold load, if you like) is required to continue inducing the  stimulus needed for hypertrophy.
What we're aiming for is  microdamage, and load progresses past adaptations (of which I'm fairly  sure are significantly connective tissue adaptations more so than  muscular) rather than volume. That isn't to say there isn't a place for  volume. But I promise I'm gaining more doing 12-15 reps and 3-5RM range  than the guy doing 5x5 and 85% of 5RM. And as we know, strength and size  go hand-in-hand. It's not a linear correlation, but it IS a  correlation. Hell, I think we can say is causal effect at this stage, we  just don't understand it as well as we'd like (yet).