Firstly, do you have the license for MPEG-2 decoding for the Pi? Most Live TV streams are MPEG2, so without purchasing the codec license you will get VERY POOR playback of Live TV to the point of making it nearly unwatchable.
I use a Raspberry Pi2 with Kodi for TV in the bedrooms in my house, and this is my @advancedsettings.xml@:
<advancedsettings>
<network>
<cachemembuffersize>41943040</cachemembuffersize>
<readbufferfactor>10</readbufferfactor>
</network>
</advancedsettings>
That works for versions of Kodi up to 16. If you are running a beta version of Kodi (v17/Krypton), the settings are slightly different:
<advancedsettings>
<cache>
<memorysize>41943040</memorysize>
<readfactor>10</readfactor>
</cache>
</advancedsettings>
I have no real issues with buffering, and I am streaming full HD streams over 802.11n/2.4GHz WiFi where buffering would be expected. So, as long as you have the license for the codec and available bandwidth in your network, give these settings a try.