I am having trouble with failing powerline adapters (losing connection). I am on the same power group in the house. At this moment I am working with ZyXEL PLA5206 - Gigabit Powerline Adaptor Starterkit - 1000 Mbps. I also worked with Fritz / Netgear. I don't know why one works better than the other. What specs should I look out for when wanting best stability / performance / speed.