It used to be an extremely rare bug for me (restricted to one character) but I swear on my new character it's quite common.
I suppose it depends on how you play. If you never watch the npc when they talk to you, you'll never notice it... It's very much disturbing, widespread and somehow random. If you play a scene, you could not have the bug; you reload the game and play the same scene again and there it is...
I personally rolled back to 1.8 and I stick to it.
I think it's completely a matter of opinion. That being said, I know there are people (PC users) that think it's bad enough to forgo the option to use mods, including the unofficial patches (which are not compatible w/out 1.9). In my opinion, avoiding the bug isn't worth not being able to take advantages of the things that 1.9 adds and fixes. Luckily, for the people who choose to stay on 1.8, the DLC are still compatible and don't require the update to 1.9.
http://www.youtube.com/watch?v=XnOVpkBpDKg
I'm sure there are more videos than just this one if you search YouTube.