Hit or miss, though I don't think that is the extension's fault. I use a VPN, and that often means that sites display things based on my IP's location, but inappropriate for my actually location. I used the extension to set a fixed location and some sites respect it and others do not. For instance, lowes.com displays the store using the location of my VPN IP address on the other side of the state, and homedepot.com uses the fixed location from the extension. I think you just need to keep in mind that different sites use different techniques to derive your location. In my case, I want the security of a VPN with the convenience of sites knowing roughly, but not exactly, when I am. That does not seem to be 100% possible with this extension, but I'll use it for a while to see if it's good enough.

Not easy to use. Too much reading. Could be simple but instead the authors want you to read pages of text to figure out how to use it. Sad because this would be a very nice thing to have. Oh well.

It does what it says. It convolutes your location. What I'd like to see is a site-specific option, so that it can be automatically disabled for certain websites. Then it would get 5 stars from me.

This is one of the most comprehensive add-ons for geolocation out there. The various levels that it allows for configuration is unmatched.
However, it doesn't serve the purpose. For one, it says it allows you to configure per site but the icon that allows it is always disabled. It's not clickable no matter what option you choose. Moreover, albeit not much of an issue, it it embedded deep into page actions.
It also annoys me when it doesn't allow you to cache the location for infinite duration. I don't understand why deny the possibility if a user wants it.
Also, something that maynot be in it's purview is that a JS request as simple as one for system.time can help a website determine your geo-location.
Lastly, it doesn't work always. Websites such as iplocation.net can still determine your geo-location even when you have faked it using location guard.
I have used location guard in conjunction with and without other vpns but it has failed to do it's job consistently.
Don't get me wrong, faking geo location is a tough thing to do and this add-on does a job much better than any other, but it is still just not enough.