So it's been nearly a week with CM13 flashed on the phone, and I finally feel I love using the OP2. Battery life I'm getting about 5-6h on-screen time, the phone feels a lot cooler under light usage as it turns off all the high performance cores (no idea why Oxygen kept 2 awake). Gaming performance also feels smoother as well thanks to all cores being enabled, and temps don't even feel that hotter. There's no random lag when waking the phone as well, which was introduced on Oxygen 2.2 for some reason. The FP scanner also seems to work faster, and it feels great to use it with other apps thanks to using the native FP API. I also don't get the random freezes which I seemed to get having the phone on after a couple of days since last reboot.
Honestly Oxygen OS was poorly optimised and was holding the hardware back way too much. The OP2 is only worth your money if you're willing to flash a custom ROM.