I have no idea how to fix this 
I have an R8000 and I have always been able to get full speed wired/wireless on all my devices (I have 330 down, 20 up). But during the last month or two the download speed on all my iOS devices has been crap, this on on an iPhone 6S, 7, iPad Mini 4 and Apple TV 4th Gen.
If I use wired/wireless AC on my PC/laptop I can get the full 330 down, 20 up instantly everytime without fail, yet all my iOS devices fluctuate between different speeds, do a test and it's 300 down, another test it's then 30 down, then 100 down, then 180, then 20. It never used to be like this, I could run a speed test and get maxed out speeds everytime on all my devices without fail.
To try and fix this I have tried the basic router reboot, wiping the router via the website and with the reset button on the back, I have even tried downgrading the original netgear router firmware, I have even tried installing the open source DDWRT firmware but the result is the same. Even tried using the Virgin superhub 3 AC router, same crappy iOS only speed.
I have also tried resetting my iOS network settings, wiping it clean and starting fresh but again same speed fluctuations. I am completely at a loss as to why this is happening.
All I can think off is if starting with iOS 10.1 the iOS wifi driver is having compatibility issues with the broadcom chipset as the virgin router uses broadcom as well, doubt this but I can't think of anything else I can try.
Here is the wifi in my area, quite a bit but none that should cause me issues.
http://imgur.com/a/90Gep
I have an R8000 and I have always been able to get full speed wired/wireless on all my devices (I have 330 down, 20 up). But during the last month or two the download speed on all my iOS devices has been crap, this on on an iPhone 6S, 7, iPad Mini 4 and Apple TV 4th Gen.
If I use wired/wireless AC on my PC/laptop I can get the full 330 down, 20 up instantly everytime without fail, yet all my iOS devices fluctuate between different speeds, do a test and it's 300 down, another test it's then 30 down, then 100 down, then 180, then 20. It never used to be like this, I could run a speed test and get maxed out speeds everytime on all my devices without fail.
To try and fix this I have tried the basic router reboot, wiping the router via the website and with the reset button on the back, I have even tried downgrading the original netgear router firmware, I have even tried installing the open source DDWRT firmware but the result is the same. Even tried using the Virgin superhub 3 AC router, same crappy iOS only speed.
I have also tried resetting my iOS network settings, wiping it clean and starting fresh but again same speed fluctuations. I am completely at a loss as to why this is happening.
All I can think off is if starting with iOS 10.1 the iOS wifi driver is having compatibility issues with the broadcom chipset as the virgin router uses broadcom as well, doubt this but I can't think of anything else I can try.
Here is the wifi in my area, quite a bit but none that should cause me issues.
http://imgur.com/a/90Gep