In the same vein as techgnome's answer:

I prefer having one "application state" object that is referenced by all three forms. This is conceptually identical to having a Module, though you have to write a few more lines of code to support it. Since it's an object reference, if one form changes a value, that value is visible to all forms. I can add events and other mechanisms to notify each Form when another changes it.

You can do those things with Modules, and many people do. For hobbyists and many professionals, that's pretty much the end of the discussion.

But my professional experience is my life got better when I quit using Modules. I could try and explain why over pages, but at this point it's a lot of "gut feeling". If you ever want to do unit testing, you'll have to wean yourself off static state at some point anyway. I think it's better to treat Modules as "a thing I use under the right circumstances".