I've kept (more or less) a log of my previous routine, as I said it's similar to this one in structure, it just had different main lifts (bench press - overhead press - romanian DLs 3x8 - romanian DLs 4x5).
I've done it for exactly three months, these have been the progresses:
-bench press: was giving me hell. At August I stalled at 155lbs (70kg) in 5x5 with poor form and poor control, so I took it down to 132lbs (60kg) and started from scratch focusing on technique. Quickly added 4lbs each week up until 159lbs (72kg) in 5x5 with good form, then progress slowed down, I'd started to need 2-3 weeks for every additional 4lbs to complete the whole 5x5 sets. I've now reached 172lbs (78kg) in 5x5, which was roughly my goal. Total poundage increased every week tho, even when progress slowed down I'd maybe do 5-5-4-4-3 the first time I added 4lbs, then 5-5-5-4-4 the following week and then a full 5x5 the week after
-overhead press: i've done it with dumbbells for months, but just in the last month or so I started doing it with barbell. Mechanics feel entirely different than with dumbbells, including the 1RM test I've probably done barbell OHP a total of 5 times I think. Started with 88lbs (40kg), which is half my bodyweight, and quickly worked up to 105lbs (58kg) in these few times, so progress has been linear so far
-front squats: same as bench press, they were giving me a hard time. I could do about my bodyweight (177lbs) in 5x5, but with poor form, so during these 3 months I went back and started doing paused front squats with about 50% of that load, working on hips and thoracic mobility. So, no full heavy front squats for 3 months, I tried them last week and managed to up the load a tad above my bodyweight (182lbs) in 5x5 with much cleaner technique. They still need a lot of work, thoracic mobility improved drastically, hips mobility still needs improvement
-deadlifts: I was doing them with 265lbs 3x3 but I had two major issues. One was grip strength, at the end of the second set my grip would start to fail and pull my back down with it. The other was that I was weak on the very initial push from the ground. So I took them off in these three months and i did romanian DLs, leg press (focused on hamstring pushes and in a starting stance similar to the one of DLs) and paused deadpulls.
Romanian DLs went from 155lbs (70kg) in 3x8 to 207lbs (94kg) in 3x8 and 220lbs in 4x5.
I've tried again full deadlifts from the ground last week with the same weight that was giving me trouble before (265lbs x3), grip strength improved dramatically using the double overhand and became a non-issue by trying the mixed grip, push from the ground felt much easier and spinal alignment improved too. I'm fairly confident I can now use that weight for 3x5 with a solid technique.
As for the secondary exercises, they increased too, but slowly. Most of them are done with dumbbells and in my gym we only have fixed-weight dumbbells that increase 4lbs at a time. So progress has been mixed depending on the main lifts, i.e. on a day where I managed to do a whole 5x5 bench press with an increased weight, I could maybe crank 1-2 more reps than previously with the dumbbells shoulder press (doing maybe an 8-7-6 pr 8-7-7), but at that point there would be no way for me to increase weight or reps on the following dumbbells bench press.
On secondary/assistence stuff with dumbbells I usually prefer to have a double confirmation before increasing the weight, that is, if I have to do a 3x8 shoulder press, I'd try to hit the full 3x8 mark, then the following week hit it again and only if I manage to do the full 3x8 again I'd try to move up the weight.
This is highly dependent on the main lift, for example if one week I do full 5x5 bench press and full 3x8 shoulder press, it could happen that the following week with the increased weight on bench press I'd do a partial 5x5 on bench press and ALSO a partial 3x8 on shoulder press.
So it could easily take a whole 3-4 weeks before I could up the weight on dumbbells stuff, with the exception of rows that I did right after the main pushing lift, so I managed to up them at a quicker rate.
As for the 5/3/1, I've eyed that program since the beginning, it looks awesome.
My main issue is that the author was very specific about customization and I didn't want to disrespect him trying to adapt his program to my needs. These are the things that I'm not sure if I can change/adapt without Jim Wendler killing me in my sleep:
-no bench pressing, just overhead pressing: as I said, when I started off I was told that my right shoulder is slightly rolled forward, which caused also a reduced scapular activation and underdeveloped right trap. Not sure if this is common or even normal, but I've noticed that horizontal pressing is much more problematic to me than vertical pressing, might have something to do with the way the shoulder is angled. At the beginning I could barely bench press 66lbs for reps, every rep would give a striking pain that started from the front delt and went all the way back through the lats and towards the scapula.
Even now, after working a lot on bench press technique and doing it pain free, I feel that I spend a ton of focus on keeping the scapulae retracted and the shoulders back, which really hinders my focus on moving the weight. Instead, when I do dips, I only need to control the descent to feel my scapulae retracting and shoulders sliding back, and when I come back up I only need to squeeze my armpits and try to push the handles down to the ground to end with shoulders back and down - it's ingrained in the movement pattern, so it doesn't really shift my focus at all.
And another article on T Nation recommended the push press (which I really like btw) as a complementary lift to avoid plateaus on the overhead press, so I'd really like to fit the push press as a main lift in 5/3/1
-front squats instead of squats: I'm hellbent on doing front squats. It's a more athletic movement overall and I like that it has more core involvement. Other than that, it requires a higher degree of thoracic and hips mobility, so by doing them I'm forced to keep those two factors in check because they tie up with my shoulder mobility too
I'm totally interested into reading the 5/3/1 program btw, if I can fit in these differences here it would be golden (i've just re-read the 5/3/1 article on T Nation and he mentions that one of the routines has more bodybuilding-style accessory work which would be ideal for my goals)
EDIT: apologies for the long posts but english is not my first language and synthesis is not easy