I came across this when viewing VR youtube videos and everyone who has tried said it made their games look much better and I thought they were overly exagerating it but after trying it for myself, I can honestly say that for most games it looks like the vaseline blur has been removed and can look close to PCVR - no lie 
You can change the refresh rate, resolution, CPU level profile, GPU level profile and finally the FFR per game and I have all my games running at 60hz, around 2048 resolution with CPU/GPU on high and FFR on high and battery life is more or less the same but games look much better.
For Quest 3 owners who hate FFR, you can now turn it off!
The app is only £10 but it well worth it imo and it also includes an OVR metrics overlay that shows you how much load your cpu/gpu is using.
You can change the refresh rate, resolution, CPU level profile, GPU level profile and finally the FFR per game and I have all my games running at 60hz, around 2048 resolution with CPU/GPU on high and FFR on high and battery life is more or less the same but games look much better.
For Quest 3 owners who hate FFR, you can now turn it off!
The app is only £10 but it well worth it imo and it also includes an OVR metrics overlay that shows you how much load your cpu/gpu is using.