I'm in Castle Bromwhich B36 and for past week I've gotten 16-36mb even though I used to get 150+.
Ever since I upgraded to the 200 package I've had nothing but problems. There's an engineer coming out Monday but now I can see you have the same problem i'm wondering if it is the router or the area 12. I would log into to use their diagnostic tool but it doesn't work and never has, it's always "temporarily down"
I have tried all suggestions to ramp up wireless speeds including trying all channels. All only result in 40mbps and we get near 200 wired which is a massive differential especially when we used to get 100 wireless.
With the Super Hub that you have it is capable of achieving the correct speeds, as when you tested through wired the results were a little over 200 Mbps.
In regards to wireless speeds, there can be many factors that will impact the speeds. It could be due to interference or even the device capability itself. For example a mobile phone may only achieve 60 Mbps whereas a laptop will hit 200 Mbps. What device are you testing with?