- SL has you start with babyweights. It will take you forever to actually start getting stronger. SS, on the other hand, tests you on the first workout and let's you kickstart progression
- SL has you add 2.5kg on every workout. This will make progression incredibly slow on the beginning, and incredibly hard after a month or two. SS, on the other hand, has you add as much as 8kg to your deadlift on the first few workouts, and it eventually lowers progression on certain lifts like the ohp and the bench to 1kg per workout. This means you will not get stuck on the 50kg-ohp-deload-loop everyone who does SL gets stuck on
- SL was "written" (copy pasted in a dumb manner and without any thought behind it) by a marketing team with 0 coaching experience, and is targeted towards couch potatoes. SS was written by an ex-professional athlete and a coach with over 3 decades of experience
- SL only has you work your floor pull 1.5 times per week. SS has you work floor pulls 3 times per week, 1.5 deadlifts (3x at the start) and 1.5 power cleans. This means you will get stronger on your deadlift doing SS, since you will be training it a lot more
- SL has you do barbell rows, SS has chinups. Chinups are a better back-builder as the range of motion for the lats is way longer. Not only that, but chinups will give you good biceps development, while rows won't as much. Only reason you should do rows instead of chinups as a beginner, is in case you can't do bodyweight chinups and the gym doesn't have an assistance machine or lat pulldown, and you're too lazy to do negative reps.
- It's way easier to finish 3x5 sets with perfect reps than 5x5 sets with perfect reps. Not only that, but doing 5x5 will exhaust you before the next lift
- SL tells you to deload too much. SS, on the other hand, only tells you to deload if it's 100% necessary
- SS trains both strength and power, and it trains your traps and upperback a lot more with the power clean