I wasn't sure about SheerSEO initially as I don't really need to focus on SEO (at least not for now) but the more I learned about it the more I realized this would be a good investment for when the time comes to address the SEO side of things for my business and decided to go with Tier 3.
As an SEO newbie, the app is a little overwhelming but I am sure it is because of my lack of SEO expertise (understanding terminology, expected behaviour or outcomes). Maybe SheerSEO can produce some sort of training/help that is really dumbed down for people like me.
I opened a ticket with them for something I thought it was a config issue (it wasn't, it was user error) and their support team got back to me right away.
As a non expert and from my own research, I think SheerSEO is very powerful and definitely worth the money... 5 tacos for sure!