I write a lot of dialogue in many of my stories. As someone else said, it's often a better way to 'tell about" wha's going on *physically, and in the speaker's head), that descriptive narration. Either one can get tedious if carried on throughout the entire story, so that I tend to switch it up. I almost never, however, use much dialect. It's partly because I don't have a good grasp of "proper" dialect and don't want to screw it up, but also because I myself would find it tiring to read much of it (perhaps that, too, is a result of my lack of familiarity). I do try, though, to create special speech patterns for individual characters - so that (even without using much dialect or slang), so that each character his his or her own unique 'voice.' Although I'm a terrible proof-reader in general (you can ask the validators), I do read my dialogue carefully to make sure it sounds 'real' (at least to me).
I also stay clear of almost any story setting or situation (including historical ones)where, to do a god job, I'd need to do much research, because that would make writing too much like work. If occasionally things don't seem 'real' to the readers on account of this, then all I have to say to them is this: :P~~~~~~~~
opb:
there's no problem at all for a detective to work on only one case at a time, get the SOC results before lunch, an arrest before tea and then to go home to a wife who says "Please spank me."
If only real life could mirror art!