The pool hashrate is calculated in the miner from accepted shares. I would argue it is the most important metric to look at since this is effectively what you're getting paid for. Since it's only based on accepted shares at the user's pool, it automatically deducts dev fee, hw errors, rejected shares by the pool, any network downtime for your rig, etc.

Your pool should mirror this value over time. We display the value since you started the miner though, pools will normally use a shorter window, so they won't match 100% at any point in time.