Awesome Tool - Wish I had it sooner
I have multiple websites, and I'm tech support for them. I've struggled a bit with DMARC, DKIM, etc. What I absolutely LOVE is that when there's a email sending problem (got one pretty fast) the system will give you an incredibly detailed explanation of what happened, how to fix it, and why.
As a self taught techie thiis the perfect tool for me. I want to fix things, and I want to understand why I'm doing them. That often keeps you from repeating the same mistakes.
The only con I can think of is that for someone completely unfamiliar with DMARC might find it a bit overhwhelming. My suggestion - give it a try. If you're not techie at all, accept it might be tough at first, and if it really doesn't work out you have the return window.