Comment 4 for bug 1492180

Same issue here.
iwconfig reports some number and it doesn't change no matter how the real rate varies depending on signal (I guess it's stuck on some initial rate).
while "iw dev wlan0 link" reports the rate properly and matches the rate I see on the router's end.

I've run this a few times and I can see "iw" reporting the rate changes while "iwconfig" is stuck at the same number all the time.

$ iwconfig wlan0 | grep Rate
          Bit Rate=144.4 Mb/s Tx-Power=15 dBm
$ iw dev wlan0 link | grep rate
        tx bitrate: 300.0 MBit/s MCS 15 40Mhz short GI

$ iwconfig wlan0 | grep Rate ; iw dev wlan0 link | grep rate
          Bit Rate=144.4 Mb/s Tx-Power=15 dBm
        tx bitrate: 150.0 MBit/s MCS 7 40Mhz short GI

$ iwconfig wlan0 | grep Rate ; iw dev wlan0 link | grep rate
          Bit Rate=144.4 Mb/s Tx-Power=15 dBm
        tx bitrate: 300.0 MBit/s MCS 15 40Mhz short GI

OS: 64bit
Distro: Kubuntu 14.04.4 LTS (using wily hardware enablement stack)
Desktop: KDE
uname -a: 4.2.0-27-generic #32~14.04.1-Ubuntu SMP Fri Jan 22 15:32:26 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux