The reviews here are very old, so I had a look at this plugin myself. I got tired of all these hack attempts, so this seemed like a nice way to keep out most of the trash. It's very user friendly, after installation you get a list of countries you want to block admin access from, and a "select all" option. Your own country is not on the list so you can't accidentally block yourself. After that, I could still access the admin section of my site, but when trying from a VM in another country, access was blocked. There was no output, just an empty page, which is fine to me. So, a simple plugin but does exactly what it should. By the way, for some IP addresses the country is not known or incorrect, so no GeoIp application is perfect.