I like this more than FakeSpot. It gives more actionable data - a revised score, rather than a grade of score strength. Sure, the reviews can get a "C" but ... should I buy the product? ReviewMeta at least adjusts the total score to something meaningful.
However, recently, the service was down for weeks with 0 communications or explanations. I would kind of expect better of a service I start to rely on. At least it is up and running again - for now.

It is great to be able to quickly look at the toolbar to see what ReviewMeta's adjusted rating is for the amazon product page I am on. One-click takes me to their page to read more in depth about the adjusted rating, or, if there is no rating, the one click triggers reviewmeta to create a rating.

I wish I didn't have to click to get more info. Like, if I hovered over it, and it gave a brief summary (like its Pass,Fail,Warn summary), that would be awesome.

Very useful, though one minor annoyance:
When I'm not on amazon, the extension's button on the toolbar should hide. I don't need a shortcut to their website, I can find my own way there. I just need to be able to see and click it when I'm looking at an amazon product.

You need to refresh every amazon page after enabling (or installing) the add-on, otherwise it just opens the front page of ReviewMeta.

(This is surely why that earlier reviewer thinks this extension doesn't work.)