I have BT Infinity 2 and BT Homehub 5 and just replaced my older Solwise 500 powerline extender units with BT's newer Broadband Extender Flex 600 units.
With my Solwise extenders I'm getting 73Mb download and 19Mb upload - just as you'd expect with any recent powerline adaptors on a strong network (ie. good house wiring and close to a BT exchange - 50 metres).
BUT, with my brand new BT 600 extenders I'm barely getting 1Mb download - and upload is not even displaying.
I'm using identical socket placements and can swap freely between Solwise and BT with the same results - Solwise 73Mb, BT 1Mb - and I'm connecting via ethernet - not wifi.
This has to be something really simple - any ideas?