A lot of reviews I read talk about this game having a rocky launch, with lots of obtrusive bugs and technical issues. Have these problems been fixed since by now?

I started playing couple of weeks ago, almost finished the game and i haven't encountered any issues. So yes in my experience it is indeed playable now.

Thanks, that's what I was hoping to hear!

From what I heard it's still a bit of a gamble, especially for Nvidia+W7 users.
I runs just fine for some, others need to use a x360 controller for it to run (no idea why though) and it's still unplayable for others.