Does anyone have any experience moving from Starting Strength to 5/3/1? Namely, when and why you did it?
I do from both a personal adjustment and from training people. I transition as such.
Starting strength till something needs to be reset. (I do the deadlift/pull up variation versus power cleans unless I'm working with somebody playing sports)
At first reset switch to Grayskull barbell with HIIT two days a week. This has a very similar set up as 5/3/1, in that you go for broke on the last set, you're doing intense conditioning, and that it has a bit of auxiliary work in it.
Then, transfer into 5/3/1 after a few resets in GSBB.
If you want to go straight into 5/3/1, you can just calculate your 1RM using your last set of five on your lifts. However, I'd get your last bit of linear progression if you can and Grayskull is great for that.
@Jala, Barbell complexes, prowler work, and some Crossfit style interval training are going to be much better for you in terms of lowering body fat and maintaining muscle. That routine seems, quite honestly, to not really guide you anywhere. You're not going to make real gains in any direction doing the same thing with the same weights over and over again.
also, lets be clear, depth squats with a pause at the bottom, band/chain box squats, power cleans, push press/jerks, band/chain bench presses are all amazing for developing power. Size is all about diet. You're not gonna go middle weight using barbells.