I generally trust the best advice out there, so I am currently following the 5 3 1 plan with bodybuilding assisted lifts (yes, I'm trying to get the best of both worlds and understand that this will hurt my gains. It's a balance and a trade off). I just want some perspective about intensity. Back in the day (late 80s, 90s) I followed a program from the football coach that had us doing bench press (for example) 2-3 days a week. Our program was very similar to 5 3 1, except a little more intense. 5x5 one week, 3x3 the next, and 5, 4, 3, 2, 1 the next. All had similar progessions to 5 3 1. Later I had added 5, 3, 1, 3, 5 to my rotation. Being used to this kind of lifting, 5 3 1 does not feel very intense. In fact, yesterday I did 3x3 and last week I did 3 x 5. The first two sets still feel like warm up sets. On top of that, I'm only doing it once a week per major lift. So I trust this is a good program. I'm just looking for people to tell me that when I was younger, clearly I was pushing too hard and that big, short, and boring combined with rest and a good diet will lead to bigger gains. On a side note: in the late 90s I switched to something similar (one day a week), but the heavy sets were still a bit more intense, took in a lot more calories and I did see amazing gains compared to the old program.
Thanks for the input!