I've had a Quest for a couple months now and i've been enjoying it but I was always confused by the people saying how good the tracking is, i've always had issues with slightly poor tracking, especially obvious in Beat Saber at anything from Expert upwards. 
I asked in here a few times and everyone just insisted I was being a retard. 

Well guess what, it turns out everyone was right! I WAS having tracking problems and the Quest DOES have excellent tracking! 

What was the problem? The gyroscopic tracking prediction. Allow me to explain.

I only have a small apartment room so my play space is restricted, it's not so small that i've actually had issues playing games but if I stretch my hands out and take a step in any direction i'm going to see Guardian boundary. But if I stand in just the right spot I can move my arms all around and never trigger it. That's my little VR sweet spot and it's been "fine". 
But the quest does something smart when the hands are out of view of the cameras, it uses information on where your hand was last, what direction it was moving in and how fast it was moving to "predict" where your hand is going to be, this works fine as i'm sure you're all aware but in a game like Beat Saber where you're making large, sweeping fast movements, that prediction can actually be quite inaccurate. Inaccurate enough that it was predicting my hand intersecting the guardian boundary for a fraction of a second. And every time this happened, causing the Quest to begin drawing, stop drawing and then redraw my boundary, within the game, it was stressing the device just enough that performance would drop. Not every time for sure but enough to be noticeable. 

By going into my guardian settings and lowering the sensitivity of my guardian boundary the problem is completely solved. The predicted location no longer triggers the boundary, which is no longer triggering the overlay, which is no longer dropping performance, so is no longer causing tracking issues.

Yay!