I loved my zipp, but after only a couple of days the power button was mashed in and the speaker required a return. Apple refunded my money.
Building portable speakers requires more than just aesthetics for intelligent design it takes industrial thought. I had noticed that the power button was flimsy when my zipp first arrived, and after travelling with it found out that it truly was. :(
Hopefully B&W or B&O options work out better for me.