Review (5/5): If you want to know which brand of these to get, get the Firefly one
honestly, there are a lot of these on Amazon so if you are deciding which one to get, get this one (from Firefly). The silicon is high quality and actually exfoliates and lathers. It is not going to lather like it seems in the informercials or social media ads you might see, but it *DOES* lather. The bristles were varied enough and engineered/positioned well enough to give you a pretty decent massage. The back scrubber can also be used to slough off dead skin anywhere - you could 100% use it on your legs or hips or wherever else you need. You could also use it to massage your lymph system as a supplement to dry brushing, which is worth mentioning, I feel.
The bonus scalp massager makes this brand's product better than their competitors. I did not intend to purchase one but after trying it, I love it too! It was hard enough to not tangle your hair while soft enough to not hurt your scalp.
The one caveat I will add is that I have short arms and a short torso, so the length of the backscrubber works great for me. If you have a larger back or struggle with mobility in your arms, you will need a longer band size probably.