Actually, I'm only interested in one issue.
The pace of fighting: is it like in PF 1e or rather D&D 5e? The shorter the better.
It does not run as fast as 5E. It is much faster than PF1. But combats are still long and involved depending on the players and number of enemies.
What you will like is the preparation for combat is much, much faster. No more PF1 hours of buffing prior to the fight and tracking ten different buff spells from casters, potions, wands, scrolls, magic items, and the like. Magic and abilities are much more like 5E with short durations only worth casting or using when the combat starts. Pre-buffing is mostly gone other than some potions and longer lasting alchemical items that are easy to track. No more of the crazy let me cast cat's grace, bull's strength, bear's endurance, invisibility, haste, enlarge, magic weapon, death ward, energy resistance, protection from arrows, summon monster, greater magic fang, and if you've played PF1 you know the long list of pre-buffing insanity that existed in that game. That is gone. Makes starting combat much faster than PF1 or 3E.
The actual fights will often depend on how fast your players make their moves and how fast you can move and take monster actions basically system mastery. It requires more system mastery to run PF2, though not nearly as much as PF1. Though it might take you longer to learn the system, once you and your players do the encounter speed will come down to you and your player speed processing actions.