Agree with every point you have made. Really don't see how much time you are saving by running straight thru. I'm a lvl 28 Titan and when teamed with like level hunter/warlock mobs fall pretty quick so maybe you save a tick or two but really do not see the point to it. Of course I see this most often when running the one off strike missions which are easy and rarely offer any reward worth mentioning aside from the obligatory rep reward.