Since 1.8, skeletons run away from wolves. That's a little improvement. But overall, they are still derpy, fall from high places, walk into lava, and sometimes teleport in front of the minecart you are riding. There is also a major flaw that if you have a mod with teleportation, like Journey map, and you use it, they do not teleport to you. So I personally take maximum 3 wolves with me when needed, otherwise they push each other from heights frequently.