ethernet from a power outlet

Amazon has a number of devices which allow for Ethernet connectivity thru a power outlet.  How do these compare with a plain Ethernet jack?  I want to do some hi quality streaming but I do not have a jack near my stereo system and I'm told that WiFi is not as good sonically as having a hard connection.
These powerline devices are very convenient and from my experience, very stable and reliable.  I can't detect any audible noise when I use them for streaming as well as for video streaming.  I have been using cheapo(less than $25.00 ea if I recall) Diamond Multimedia HP500AV models for about 4 years now with no troubles at all.


Doug, this is a somewhat belated thank you but I did want to say thanks for your feedback,.  I purchased an UltraRendu, netgear 1200 and am in the process of ordering a power supply from SGC.  One thing is that I noticed Sonore did not include an owner's manual.  Is there a link to an app?

We're very low tech. here (LOL). 

Russell, you are on a very good course with the SONORE and SMG gear (reviewed for Glad you are gaining ground. :)