For Step 1, yeah weapon is great as a third line bank. I had a retired attending recommended it to me. It has really good explanations, has techniques that show you how strategies on how to deal with certain types of questions (which I haven't seen on UWorld or any other bank), and for certain types of questions like neuro it will give the same 5 answers in a row multiple times, and will show what differential fits with what answer. The "test weakness" button is brutal too, it will pinpoint exactly what you suck at.
Ultimately all the banks have the same clues and concepts, it's just more practice if you go to a 2nd or 3rd line bank. If your foundation is weak (like mine was when I first started studying), you need more practice, but if your foundation is pretty good UWorld is all you need..