As a WAR main, obviously I'll check people's gear at the start of a run and get a feel for the party on the first pull. If the group really isn't up to snuff, I'll slow down.
Really though, on experts and level 60 content in general, I very rarely feel the need to do so. Unless the healer is basically asleep, I can get through the final boss-to-boss pull of Gubal HM with even mediocre DPS. It does get oh-so much easier with Holy/Gravity spams or a properly DoTing SCH, however.
