I've just finished this game after 80 hours of playing. Unlike most games, I paid full price for this instead of waiting for a steam sale.
In general, I am satisfied with the game. I think this represents hope that there will be more games that would follow the style of Baldur's Gate for years to come.
Now, here's a more detailed assessment of the game.
Performance and Stability
The game ran smoothly on my 4-year old PC. I have not experienced any CTD's nor choppiness. I believe the game has been quite well-QAed, which is very important because a buggy game that crashes all the time can easily earn its place in the dust bin.
Graphics
I like how the uses an evolved version of the Infinity Engine. Not only does it bring nostalgia, the engine does work remarkably well for an RPG. The game looks like a 3D version of Baldur's Gate, which is what many of us had dreamed of when we were kids.
The character models are still relatively rough for a 3D game, but it's still much better than the paper dolls in Baldur's Gate which looked ridiculous.
Plot
The plot started out strong but kind of petered out after Gilded Vale. As others mentioned, the player never really was directly affected by the Hollowborn crisis, which was a central theme of the game. One thing Obsidian could've done was to make those yellow-named people the Hollowborn children. This could've added a little to the shock value.
Another thing that's quite flawed is the whole Watcher identity. The game really explained why the player was spared and became a Watcher or provided any sort of urgency on his conditions.
There are also other smaller bits of story that I find weak. The whole Magran and Skaen conspiring with Woedica came out of nowhere. Also strange is that Durance never interacted with Magran in that temple even though he could hear her.
Environment
Despite the mediocre plot, the overall atmosphere of the game was well-constructed. Each town had its own theme, history, and personality. Even the dungeons and countryside were sprinkled with tiny descriptions, which adds to the overall richness of the game.
Gameplay
There are several key improvements in the game that I consider to be very important. Having faster movements and mass looting speeds up the game tremendously. I absolutely loathed the crawling speed of Baldur's Gate 1 and I'd cry if I had to pick up 12 kobold daggers from the floor individually.
The stash is also a nice touch because inventory space came at a premium in all the previous games. Coupling that with the honest merchants in the game (who buy everything from you at full price), it makes looting that much more enjoyable.
Another thing I like is the original design of the classes. The wizards of the game are a union of the mages and sorcerers in D&D. It sucked not being able to learn spells as sorcerer and it sucks having to guess your spell splots as a mage. You don't need to go through that crap as a wizard in this game. The chanter and cipher classes are also quite unique. I've never seen games that use their spellcasting systems. Finally, the per-encounter skills/spells come in quite handy. It gives the player reason to use some spells in each fight and not try to hoard them.
The crafting and enchanting system are a nice touch. They feel a bit limited but I can't complain much when they weren't really existent in the previous games.
On the bad things. The first thing that comes to mind is the lack of pre-combat preparation. In previous games, it's often a good strategy to buff the party before a fight. Another substantial downside is the lack of multiclassing and multi-focus. You can't take 3 levels of wizard and progress as a fighter in the other 9 levels. You also cannot be both a stealth and a mechanics master because the skill cost becomes ridiculosuly expensive at high levels.
Overall
Pillars of Eternity is a good continuation of the Baldur's Gate/Icewind Dale RPG lineage. It's not exceptional in quality but is still worth of 60 hours of attention especially given the budget.