I have a couple of spark lites, and I like them a lot. I'm not sure if I'd like the aluminum, especially if it were cold, which is usually when I'd expect to want a fire the most. The obvious advantage is one handed use, but it's also handy because the sparking motion is less likely to cause you to bump into the tinder, moving it around.

Today I bought a roll of jute twine. $1.50 for 150 feet. It's not as nice as cotton string as far as string goes, but it lights way easier. So far this is the only solid household product I've been able to light with a spark. (Liquid fuels are easy, as are the commercial tinder tabs that come with the spark lite, and magnesium shavings.) At $.01 a foot, I now have little excuse to not have tinder everywhere.