Bands are great if you implement them right, i.e. to complement free weight and provide progressive resistance. They are particularly useful for exercises like jump squats, explosives, etc., where you can apply just enough band tension on the bar to keep it from leaving the shoulders at the top of the lift. They are also great for getting through a plateau, accelerated eccentrics are a great tool in the right hands.
The thing not to do is try and go into a band only training mindset, the free weight should almost always grossly outweigh the band tension. There are alot of rehab, prehab, activation exercises like band pull aparts, shoulder dislocations, x band walks, etc. that are also very useful.
