Guys. Chill! Interesting discussion.
I've not noticed any WiFi issues with my new 10 but decided to do a quick test: using the app WiFi Analyzer on the channel view, I put my 10, my OG Turbo, and my M7 side-by-side and walked around the house, into the back yard, and out into the driveway in front. My favorite surfing location (the "throne room", three walls away from my router) has the worst reception in the house, but fairly consistently my 10 held a 10dBm+/- advantage over the Turbo, and held onto the signal longer as I walked away from the house on the front sidewalk. FWIW, the 10 seems to have a more sensitive (?) WiFi antenna, consistently showing more of my neighbors signals than the Turbo. Ironically, my M7 generally held a 3-4dBm advantage over the 10! Bottom line: the 10 is better at WiFi than what I've been used to for the past almost two years, which is good enough for me!
PS: I fail to see how the state of a wired network can affect WiFi range; you can have a strong WiFi signal even when your internet cable or fiber is disconnected from the wifi router (try it!). The "strength" of a WiFi signal should be related solely to the power/physical configuration of the wifi antenna (in the router or extender), the distance between the antenna and the receiver (the phone), the signal obstructions between same, and the efficiency of the receiver's antenna in "catching" the signal. In my test (and the OP's) the only variable is the efficiency of the phone's receiving antenna.
A problematic network can affect connection state (I can't connect to the internet) or throughput/speed (my internet is slow) but should have no effect on wifi range.
Sorry... too much time on my hands this afternoon!
Posted via the 10