I'm also tempted to buy a dbl pump! Eyeing for Medela Freestyle. Currently using pigeon single pump but I guess when I go back to work, I might only have 25 to 30 min per pump session. So dual pump is more efficient... As to whether milk supply will increase if use dbl pump, I'm not too sure but if you realise, if baby is suckling on one side or if we are pumping on one side, the other side will leak as it is also being stimulated. So having a dual pump not only saves time but the leakage will not be wasted.