The best tool for smashing is the one that lets you get the job done. For that reason, it’s good to have a variety of tools with different stiffnesses. For areas that are particularly sensitive, hard and acute tools like a barbell might not be the best option because they won’t let you relax properly and actually get any work done. On the other hand, areas where you have big strong muscles that are crazy stiff may not benefit a bit from softer tools. They just don’t make a dent.