I would leave the tail on. I have found that if the tail is slightly to one side intead of directly underneath the unit will climb my stairs better but it tends to make it go into a circular path a bit. Hose length and float position are important for proper climbing and good coverage. Leaving the hose straight in the sun for a few hours will take care of the coiling. It will clean better then. If the backup valve is pulling it out of the ladder then it's working properly! Mine is running at about 43-44 rpm. That's the highest it will go on my system. Mine climbs the walls pretty well and gets maybe a foot below the suface of the water sometimes. Usually it will go up a bit more than halfway in the deep end. The cleaner does spend more time in the deep end than the shallow end but my returns are in the shallow end and that might have something to do with it.