Though LG has moved to the Optimus G2, there are folks with the LG Optimus G on the Sprint network. You folks get some CyanogenMod love today as the CyanogenMod team has added support for the Sprint LG Optimus G LS970 and the version is 10.2 which means your device would run Android 4.3 Jelly Bean.
The first nightly build of the CyanogenMod 10.2 is now live on the CyanogenMod website and can be downloaded from the link at the end of the post. The size of the zip file you need to download is only 189.92MB which means there won’t be any bloatware and you will enjoy pure CyanogenMod that should work with blazing speed on your Optimus G.
That said. you also need to download Gapps for Android 4.3 from goo.im and place both the ROM zip file and Gapps zip file in your device’s storage after which you need to boot into CWM and flash both zip files. But before you do that, make sure you do the 3 famous wipes – data, cache and dalvik cache. A backup of data should be available on your device storage if you don’t sync it with any cloud services.