There are some good considerations here. I'm currently most interested in fire starters for when I go off piste snowboarding. The issue of temperature keeps raising it's ugly head, thanks for reminding me.
I've had the plastic version for couple of years and just recently bought the aluminum version too. I'm a fan.
That said, for your intended cold weather purposes, consider too that the Sparklite is small and isn't the easiest thing to grip and use one-handed in
any weather, especially if you've got good-sized hands. Gloved or cold hands would make even more challenging.