Miked8c, the first week of workouts I used the boring, but big and 1 other exercise.
I definitely think the boring, but big would be good for size because for example I used 135x5x10 and did smooth, but fast reps. I would walk to the fountain to get a sip of water then walk back and immediately do my next set. So probably right around 45 sec to 1 minute rest between sets. By the 4th and 5th set the last 2-3 reps were pretty hard.
I have used it on shoulder press every time for the first cycle though I used db's. You definitely get a good pump and burn going. The weight isn't heavy, but you already did your 1 serious heavy set so now you are getting volume with lighter weight and pretty solid intensity if you keep the rest between sets short which is very typical bodybuilder style training.
5-3-1 is extremely versatile. Today is my first workout of cycle 2 and I'll be doing squats. My job is physically very demanding and it's going to take a couple more weeks easy before I really adapt to the stresses it's placing on my system so tonight I'll push my hard set of squats as hard as I can and if I'm feeling really taxed I'll call it a night ie. I ain't doing jack shit option.
Good lifting man, I see your strength going up steadily.