I used the OnePlus 3T for 3 months on the OxygenOS to have a taste of Google certified Android build.
It has nice features like Double tap the Back button to sleep. There are other features like Shelf, but I did not try that as I was using Action Launcher.
Due to an extremely active mobile battery active in version 4.1.7, I decided to jump to LineageOS. At first, I was apprehensive of getting Singtel Dash to work, but Magisk Hide did a great job. Other apps that need to have root hidden are Pokemon Go, Concur and Grab.
Lineage rising from the ashes of the #christmasmassacre of Cyanogen and CyanogenMod still has the same kernel performance, bad.
I have noticed the battery dipping aggressively. This is after several weeks of monitoring. Sometimes the LineageOS service will be always active for hours. In the end, I flashed Boeffla kernel and battery performance improved.