Manual work will always be more powerful and effective because you're exerting more energy from the inside. Also it's a full-body workout. I use my legs, arms, ass, and abs for all my workouts.
But tools like
SG is appropriate for extended healing, since we can't walk around bent over with one hand in our pants LOL!
But you can also do manual work within PE devices too, like
BM Hardcore Stretches for instance. But solely letting devices do the work is kind of like just doing weightlifting without getting your core muscles corrected and strengthened first.
I feel that before going into PE tools one should condition the penosaur with manual work.