Wireless Log question

I have a RT-AC66U (AP) and a RT-N66U (main router) both running FW 3.0.0.4.374.39 and have wireless devices connected.

When I look at the Wireless log on either router I see a report somewhat different from the other. For instance,

• The RSSI value indicated in the AC66U log appears about what I would expect when I consider the distance of each device from the router. The values indicated in the N66U log however look really good. Too good when I compare them to the AC66U.
• the AC66U displays RSSI as a negative number (i.e. -66dBm) while the N66U displays this field as a positive number (i.e. 16dBm)
• the AC66U log does not contain a "Name" field for any of the connected devices while the N66U does (albeit, most names are missing).
  
• the AC66U only displays only some of the IP addresses where the N66U displays them all

why the differences?