Is PDAF a HOAX?

Honestly: One of the reasons for me to sell the NEX7 and buying the NEX6 was the PDAF, because I found the auto focus on my NEX7 quite slow. Now, comparing the focus speed of NEX6 to my still beloved NEX 5N ,after having done all these lens upgrades, I  really don't see & feel any substantial, if any at all, difference to my still beloved 5N. Ok, there was a new lens firmware, I can display some fancy little crosses on my NEX6 viewfinder that are said to show PDAF-sensors. But they don't turn  green when I auto focus or give me some other sign of operation, they are just there, silently and not really necessary. But in the autofocus performance, as said I can't figure out any difference. Has anyone ever really felt a huge improvement that PDAF should actually give? I haven't read/seen convincing reports on that, but maybe I haven't found them yet. Or has anyone actually SEEN the PDAF-sensors on the sensor, maybe under a loupe or microscope? Because I don't, the sensor looks all flat and uniform to me. Thus my question: Is PDAF a HOAX maybe? I am starting to wonder.