I am in the process of returning this pump after 2 months of use (Dec 2012 - Jan 2013). Too many times the milk is sucked up in the tube, and even spills because it is not letting down into the bottle - very annoying. Not convenient for travelling either, as it has too many parts to walk with and the tube should be longer (the Deluxe Single pump is most convenient for travel purposes - just get a good brand battery).The motor's hum is tolerable but could be quieter (horribly loud on the single deluxe). Very disappointed in the infamous Medela brand on this item. I have to pump a lot for my preemie baby so I rented the Symphony and it works great with a low hum! (just not portable). Currently checking out the knapsack one to see if I should buy it...