Sir, I was working with resistance bands, calisthenics, and dumbbells before I gave a try to S&S. And recognized very quickly a hidden and undervalued value of the program for sedentary people.
I figured out that, I can’t raise my arms over my head, I have recognized that I can’t squat due to ankle and hip mobility, I have recognized that I can’t fully open my hips nor bend reasonably, leave a side that I can’t touch my toes.
With different tools, modalities , I was successfully training my muscles by not addressing the fundamental issues that I have and I was kind of surprised why my strength gains don’t transfer to my daily life that much. It was because simply I was able to avoid most of the natural human movements. So strength gains were not being transferred to real life.
S&S turned out to be a longer journey for me than I expected, some of the reasons are my structural issues in my body as well, not only range of motion.
But I am improving in every aspect. I did not even start the program officially. I am getting prepared. Indeed book is enough to get started however when one sats read the book and do what it exactly says is deeper than you think. For example it suggests doing naked get ups until your are comfortable. I did lets say 10 of them. Indeed for some it might be enough, but for me I indeed needed thousands of them due to Range of Motion problems.
So I suggest you take a class from an SFG certified coach or find a solid beginner program which there are abundant of them including SF online S&S course . My choice of programs are Kate’s dojo KB fundamentals and Brett Jones Mind The GAP.
Do start S&S. Don’t look back. Don’t hop in between programs and enjoy your gains.
There are other programs that will give you more muscle or more strength or more endurance or more range of motion than S&S, but S&S gives them all while keeping everything less complex.
Only a person who lived a long sedentary life can really conceptualize this value of S&S.
Once you hit Simple standard. You will be much better than everyone around you in terms of fitness in all aspects unless you live in a few selected areas in the world, including much younger individuals than you. Very few programs can give you this (Most of them will excel in one or two areas but fail in others that is being covered in S&S).
If you are engaged with other form of activities then it is still a great program because if you are already active you are fit enough not to be drained from S&S and you can keep on your existing activities.
As you might see I am a fan of S&S and probably biased. Nevertheless, Pick any SF program, execute it as written and you will thrive.
Strength to you.