I am an SEO manager and a longtime user of MOZ and SEMrush, and I just found out about SheerSEO! It looks very well built, has a competitive toolset, and is very promising! The dashboard is nicely laid out as well and it has similar metrics to other tools.

I usually like to try most of the SEO tools listed here on AppSumo just for grins (I have like... 4-5 now), but this one is extra impressive. SEMrush is historically my favorite for doing backlink checks, so I will have to see how well SheerSEO compares with time. 5 tacos!

If I could add one thing it would be more Domain Authority metrics. (note for the future!)