Hello,
We (me and a friend) just completed our first 70h long play-through and there are a couple of things I'd like to share.
Having not played the beta/alpha before, we chose two chars, 2h warrior + mage (all schools) and played it on hard with no companions.
Surprisingly, the early levels of the game were truly hard (as it should be when playing on 'hard'), and really enjoyable. We had to think how to solve not only the many puzzles (we didn't search the net for answers), but also how to do each fight.
And then, at the end of the first area we discovered the 'Lone Wolf' trait and since then it was cakewalk. The only challenging thing were the puzzles, and I feel the quality of those slightly dropped near at the end too: a few just outright required high perception (something you won't have with you at all times realistically).
Especially disappointing was seeing how much resistance you can get with the resistance gear/trait. The warrior had everything except tenenbrium at 100+, meaning most stuff just heals him, while the mage also ended up with decently high resistances (in the 80+ range). Leech also seems a bit too strong - it tends to heal 50%+ damage and more often than not more than the total taken (meaning the warrior is really vulnerable only to tenenbrium).
A minor thing that I also find badly designed is the crafting system. It's just not something I'm willing to spend time with trial and error (saving and loading..), and it really didn't feel intuitive: for that we ended up just using the crafting guides from these forums.
To end things on a more positive note, this is probably the best RPG I have ever played, and I was playing the genre since the Baldur's Gate times. The awesome parts of the game far outweigh the bad (e.g. I like how there's no 'romance' unlike in most 'new' RPGs since KOTOR), but it's much easier to write the things that disappoint.
