@Kevin_Z 

Dear Kevin,

thank you for your effort in helping us with our problems but please inform tp-link developers that customers are not paid to be quality test engineers. Instead we pay our money to get well tested and reasonably bug free products.

i mean when tp-link issues a firmware that drops the wifi performance with every client (pc, android, iphone etc) it means that the engineers did not even tested the speed with a single device. They made the changes, saw that devices mostly connect and issued it expecting the customers reaction and problems. 
This is completely unprofessional and totally unacceptable not to mention partially illegal as many times the devices lose their advertised specifications and capabilities.

Thank you again and please pass the message