Speed ​​unconvinced.

I am currently using an ancient Allnet Powerline adapter pair ALL1685 (gross 85Mps effectively 25Mbps).
To get to a faster transfer rate I ordered the TP-Link pair (500Mbps).
The exchange was not a problem. But the rate has not increased noticeably.
Then I made a test on a double socket, so same phase and optimal conditions.
The network has a transmission rate without Powerline approximately 7500 kB / s (about 60 Mbps).
The Allnet Adappter interposed resulted in a transmission rate of 1150 kb / s (approximately 8Mbps).
The TP-Link pair the transmission rate to just 1 300 kB / s (about 10 Mbps) has increased.
That I can not expect more than my network speed of 7500 kb / s is clear to me, but I would have a clear over the old Allnet adapter expects.
I do not see that there is to go wrong. The equipment and installation are actually foolproof.
So no advantage of the investment justifies, therefore device back.