I get around 15mm distance consistently.
I am also looking into rolling my own using a PIC so I can pump the coil with more energy than I am getting with the 3.3v.
I am more comfortable programming PICs but with the forum's help I am getting to know this little ESP.
Next thing is to have several and have their 'approved' tag IDs be sent out using Telnet I think.
Regards.
- Albert Einstein