The Magfire, like other similar fire starters, will start a fire if you use it correctly. BUT the main issue with spark-oriented starters is Tinder, Tinder, Tinder and Tinder.
The reason that vaseline and the so-called "cotton" balls (they are actually a synthetic usually - especially if they are called "cosmetic puffs" are such great tinder is that they are solidified oil - petroleum. They are a hydrocarbon burn, with horrid black stringy smoke, and they work great.
My magfires light them in an instant, as will just about any other sparker. They burn ultra-hot, will dry other stuff that then can be fed on the fire.
I carry a Bic lighter too - while I practice with the Magfire all the time, the reality is that it's easier to produce fire from a liquid or gas-fueled appliance in most cases. This is why there are so many billions of Bic Lighters out there. That said, a Magfire is a metal stick, with no moving parts. 100% of the useable part of the tool is availible - unlike a Doan block, which hides 50% of the striker in the block. A lighter with a wheel and valve of any kind can fail at any time. Wind and all that is an issue no matter what you're using to start a fire, but cold is NOT an issue. As I'd like to point out, the last thing you need when you slip and fall into a hidden stream while out hunting on a 10 degree morning is a lighter that won't light because it's too cold.
My Hunting PSK - the only "real" PSK I actually need - has a Magfire, Two film canisters of vaseline soaked cosmetic puffs, a Space Blanket Bivvy Bag, some trail tape, a whistle, six large hand-warmers (the type that heat when exposed to air) a magellan GPS 100, four lithium batteries and a roll of flat duct tape (which is my fuirst aid kit). I have a knife on my belt, and of course, a gun (M6 Scout, if anyone cares). I'm dressed for the weather when I go out, and as I've learned over the years, I wear waterpoof boots and gore-text rain pants UNDER my regular pants. the point is to stay as DRY AS POSSIBLE. The denim acts as a physical barrier to brush and bramble, is quieter than the gore-tex and the gore-tex keeps me dry under my layers.
The one time I NEEDED a fire when off in the woods, I had stepped into a hidden stream, hooked my foot on the ice, and fell, face first, into the snow over the thin ice and got good and wet. I needed a fire, big, and fast. Anyway, back to the point. I like Magfires so much I sell them (special sale coming next week!) because I don't like machines that fail when you need them.