I just finished Act 1 and am a completionist who literally inspects every chunk of map, reads every book, finishes every quest-log item before moving to next map area. I can safely say that Act 1 has been amazing for me.

I did encounter one inventory bug. Prior to patch one, I was using the Chest of the Mundane as a poor man's Bag of Holding due to the weight reduction. At one point I took 600kg of items out of the chest to sell them to a vendor, and my inventory bugged. After screwing around with my buggy inventory for an hour (having fun earning infinite money from a vendor, for example), I reloaded from the save prior to taking the stuff from the chest and removed it in smaller chunks and everything was fine. Patch 1 killed the weight reduction in the chest, so it is unlikely others will find this fun bug.

Side note: my Lawful Good Gold Dwarf Cleric of Moradin has been a blast. I first talk my way into any circumstances, because one shouldn't pass judgement without all the information. But after judging them as evil, wiping out the goblin, duergar, and zentarim camps has been super satisfying. The completionist in me worries about plot implications of these judgements down the line, and what I get locked out of, but so far it's been great.