If I didn't make it clear in my introductory post earlier this week, the Firefox Flame
marks my first-ever experience with a dual-SIM device. I can think of at least two scenarios where this would be useful: When you're travelling you could use a local SIM for data and not miss any important calls or texts from home. And when you're at home you could use a cheap, prepaid SIM for calls and texts and another for data with a more affordable tablet or hotspot plan.
That's the theory, anyway; let's see these duelling SIMs in action!