While doing the overland quests I read the text, because I read faster than the character can speak. In group activities I just skip the conversations so that the groupmates don't have to wait and idle while I have a chat with a NPC. I can read the dialogue afterwards from the internet if I am still interested in the story.
I read through it, or even skim it quickly now as I done all the quests before and listened to most of the dialogue the first time round on my main. New quests I still listen to 90% of the time (read it all) depending on the voice acting. The most interesting/emotional/well voice acted/favorite npc's can do their full voice acting again the second time round if I have the time.
Don't read all the books though. i tend to skim them quickly if they seem quest related. All others go into my library for later reading if i feel like it. There for sure are quite a few worth reading. It just takes to much of y playtime.