CyanogenMod can take a phone with a not-so-good software experience and turn it into something that feels more like a Nexus. This is the kind of treatment it can now give to the T-Mobile and international variants of the LG G4. 12.1 nightly builds running Android 5.1.1 are now ready for you to download and flash using your custom recovery of choice.
To download the ROM for the T-Mobile model, look for codename h811. The international LG G4 goes by h815. And if you can't do without those Google apps, be sure to grab a Gapps package on the way out.