I'm a nay, which is surprising as I usually love gadgets! I always wind several bobbins at once when I get down to my last one, then store them in the tube they came in (Bernina). There are 8 bobbins in the tubes I buy at the dealer ($8). If I didn't have those, I'd use pill bottles - what a great idea!
I will admit to having slid the spool I am sewing with off the thread holder and slipping another on to wind bobbins w/out unthreading my machine. Threading is lickety split until I get to that darned needle... I broke my auto threader & can't for the life of me thread needles late in the afternoon or in the evening.
At our give/trade/sell guild meeting there were a few of these being offered to takers.