I noticed this plugin keeps counting down, which actually made me delete it. First I installed it and used the default setting of 5 attempts and tried to see if it worked. It did. I mistaped the login later and the count went down to three and two, so I set the limit to 8 attempts. When I mistype again later (another day even), the counter keeps going down. Wouldn't it be wiser to make some kind of time interval for a few hours after which a certain IP is cleared? Also, the plugin gives the IP in the options screen, but without the option to exclude that very IP from the lockdown. I just didn't trust from not being locked out after some mistypes in the course of some time.
(Now I installed one that doesn't count, I may trust that one even less!)