Ditto...I like the fact that I can throw them in my bag (literally), drop it, get it wet (SOAKED), ran over, etc., and my batteries and spare bulbs will be fine. It can stay in my bag for months with stuff being chucked in there, with no damage. I never have to "make sure my batteries are safe". Put them in spares carrier, throw them in your bug out bag/glove box/tool box, and forget about them until you need.
I have 4 currently (owned 6 at one time ,but gave two away too family since they were so good), if that tells ya anything. The SC1 is for 6 Batteries and a P60 Lamp; SC2 for 6 Batteries and millenium lamp (M3/M4/M6), and the SC3 holds four batteries and an E-Series lamp (MN01/MN02/MN03).
Hope this helps in your decision making!