The greater story is a bit of a juxtaposition. It appears to be a little "by the numbers" with evil tyrants, religious wars, and a number of setting and story elements pertaining to souls. The characters, writing, and story are solid, as expected given Obsidian's pedigree. However, Pillars of Eternity's commitment to player agency makes it significantly more interesting than the base components. Rarely are situations black and white, and you're rewarded for digging a little deeper, though it makes the final decisions all the more agonizing. This is one game where you'll want a firm idea of how your character would operate or respond.
During these decisions, Pillars of Eternity gives you a ton of options, but many of the more favorable interactions are locked behind skill checks. This ties back into it being worthwhile to have a diverse array of solid stats. Do you have enough Might to intimidate a drunken mob? Is your Intellect high enough to deduce what's really going on? This leads to a great connection with your characters as they are more likely to solve problems in line with how you'd expect them to. Your Barbarian isn't going to diplomatically talk the situation out; you're probably just going to punch someone really hard.
It's worth noting that there is no character experience gain for getting into every single fight. You're rewarded for exploring and engaging with the world and quests, not simply grinding monsters. There is still loot to be had, though. This harkens back to some of the original Dungeons and Dragons rulesets where you got very little experience for monsters. Sneaking past a nasty encounter and stealing all their treasure - along with the quest items - is just as valuable to advancing your character, once again reinforcing your player agency to tackle challenges in a variety of ways.
Inevitably though, you're going to get into combat which means using Pillars of Eternity's real-time system, though you're going to be heavily abusing the pause button. If you've never played an isometric RPG like this, it ends up being a pseudo-turn-based system. You'll pause to give a bunch of commands and get a feel for the battle, and then unpause to let it play out for the few seconds. If everything is going smoothly you let it run or can hop back into pause to adjust as needed. There is an additional option to run the game in half time if you'd rather not jar to a halt all the time.
The combat is all built upon the notion of action speed and recovery. For instance, there isn't any arbitrary reason that any class can't wear certain armor. Heavier armor just means you're slower to make your next action. Maybe it's worth it for you for your wizard to be a little slower on subsequent fireball in order to survive melee combat. The combat is tactically fun, and you're rewarded for figuring out weaknesses and crafting an ideal party with a game plan. There are a number of characters to recruit in the world, but you're also free to hire, and custom character create, adventurers - akin to Icewind Dale, making it even easier to fill in the gaps of your perfect group.
The only time the combat really runs into problems are when occasionally a fight drags on to a stalemate. Usually what happens is all your other characters except your heavily armored fighter are unconscious and you've used up all the available skills. So you end up playing random number generator with an enemy or two into tedium. My only other gripe is that at times a big cluster of characters can get a little too busy, and it will be hard to make out who is attacking who and which characters are currently engaged. Though is a problem more inherent than Pillars of Eternity specifically. Engagement is important to have a handle on because it replicates the attack of opportunity of other tabletop games, so archers and magic-users can't just keep running away nor can melee rush past your defenders.