At least main quest and companion stories should be voiced in my opinion. :P
I tend to get bored with just reading blocks of text but if there is a voice, I usually listen to it in full.
100% agree!
Most people read much faster than they speak, meaning that I've read a dialogue 5 times before the actors are done speaking. For any game with a meaningful amount of dialogue this is terribly annoying and it doesn't take long before I just start skipping ahead once I'm done reading instead of waiting for the voice to catch up.