I really don't like them b/c I've had numerous issues with the mag not being that good - in other words, barely worth the effort. I'd rather throw a Hotspark into a 35mm tin with vaseline gauze. Presto, you're own striker/tinder block.

Blowing away mag shavings? Yeah, ok, it happens. My thing is using a file, or peeling off shavings with a knife, either way they go up so freaking quick that my other tinder doesn't have a chance to catch. I've personally had better luck with regular old birch bark. though I suppose I could try the mag shavings on the birch and see what happens.

My other big gripe is that with the big bar of mag, I find it hard to aim the flint easily. Resulting in awkwardly-aimed sparks.