I can clear Toto-Rak in a little over 30 minutes with a pair of fresh DPS as long as I'm controlling the dungeon by rolling tank. I'll choose whether to hit up the side rooms or not (normally I do since for anyone not 50 this is an exping dungeon run and I respect that) and if we don't hit side rooms that dungeon can move along nicely. Stone Vigil can move fast too though it's a bit more of a crap shoot. Anyways...let's say it takes 45-50 minutes in an SV because a newer DPS catches aggro and the group wipes...assuming you requeue low level roulette again after you ditch us you've used up the 30 minutes of the penalty AND now unless you get a Primal Story Mode you're probably still looking at at least another 30 minutes worth of dungeon. Instead of being done your roulette in 45 mins or so you've now used up not only that 45 minutes but another 15-20 depending on how well your replacement dungeon goes (which could be the same dungeon FYI)