If you played the game only once right on release, chances were high, you didn't notice many bugs. That is because many bugs were just stuff missing or not triggering. You notice that stuff more on multiple playthroughs and by reading about other peoples experiences.
Apart from that, for me the release version or maybe patch 1 were still the best. At least my experience got worse from patch to patch.
I'll say that the release version was stable for me and I don't remember any bugs, admittedly it was quite a while back and on my first playthrough things may not have triggered where they should have. But patch 3 introduced so many bugs that I had to revert to patch 2. Just FYI my game is not moded.
