Like I said captain, I suspect my router, as only when bypassing my router do I recieve the full 150, i get 120 from the router, and 90 via powerline.... so my first degradation happens there.
Most decent powerlines come with a network securing property.
Wifi is usually a higher tier addition. However most suppliers allow you to make networks of multiple units so you don't have to buy full sets of the expensive ones, I have two netgear passthrough adapters (bought as a pair) running the downstairs of my house and a 3rd pricier wifi + ethernet unit in my upstairs bedroom, which came with a fourth ethernet only block which is still in box with no use for it yet.
Wifi bundle
https://www.netgear.com/home/products/networking/powerline/XWNB5201.aspx
Ethernet only passthrough pair
http://www.netgear.com/home/products/networking/powerline/XAVB5421.aspx
Hey I was wrong, they were rated for 500mb/ps not 300

Still higher than my incoming connection
😀
As an owner of these I can tell you the manuals use generic instructions, and the timing needed for the security connection button is more or less a 1 second press and release, not a 5 second hold as it lists in the manual for other models.
Took half an hour on the phone with their support to get that out of them, only device I've ever encountered where holding the button too long made them lock up and need factory resetting to unfreeze
😀
Just to be aware of if you were to use them. Also the wifi plug doesnt like being enclosed, so keep it in a ventilated space, not jammed behind furniture with only 1 inch clearance, otherwise its prone to overheat and need rebooting after 8-9 hours use.
Decent suppliers will be happy to tell you which of their sets are compatible with others they produce too to prevent you picking a lemon