My second favorite thing about the Darwin (or is it my fourth favorite...no battery purchase, USB chargeable, don't have to check atty ohms...) is that its rugged. Fifth favorite is that this little sucker doesn't roll. If my Silver Bullet falls off the night stand it can begin quite the merry journey. Wherever the Darwin kerplunks is where it will be when I reach for it. Since it lays down flat it doesn't really go kerplunk though so you gotta love the form factor.