For me it'll depend on if there's any related quests or if dogmeat actually plays a part in the story and how she acts when I"m trying to be stealthy. The main reason I've not liked companions so far is that they are stupid..and do really stupid things. If they've somehow fixed that then companions could be pretty amazing. Of course the main reason I didn't like dogmeat in fallout 3 was because of her constant panting. I just found that noise so grating and annoying that I couldn't stand having her around.
At the moment I'm planning not having.. though I'll pick up all the companions I can and send them to a settlement or something if that's an option.