I was generously given the 1-hand and mini mag/flint bar by Ranger Rick for evaluation. My thoughts:
I had a chance to test RR's 4-finger fire starter. Essentially, it's the top of a cigarette lighter. It contains a ring on the bottom, which allows the user to put a finger through it and balance it while striking the sparker wheel. I found it to be a nice, compact package, that quickly lit the tinder tested (cotton balls, Coghlan tinder, dog hair, and dried grass). What I really liked about this device is that it felt very stable - it didn't wiggle around and disturb the tinder pile that I had started. With it's size, it's easily joined my EDC supplies. Also, it does have room for at least one cotton ball, allowing me to carry some ready tinder in case it's ever used. This is, to me, a significant advantage and selling point over other single-hand strikers.
I also had the chance to play with RR's flint/magnesium bar. It's about the same length as the normal Mag bar that most of us know, but about 1/4 the width of that bar. The included striker did take about 10-15 scraped before it effectively began throwing sparks. It did a good job of scraping magnesium off, and did thrown off an impressive shower. One thing to note is that it is NOT sharpened, so it's appropriate for EDC or soft-carry packs. Of course, the striker could be sharpened to make an improvised blade if desired. While effective, I did notice that it had a similar drawback as the full sized mag bar: striking it can disturb the tinder pile and mag shavings. As such, I plan to use it as I do a mag bar: a back-up fire starter, most likely left in a daypack and forgotten about. The really nice thing is it's size. It weighs significantly less than the full size mag bar, meaning that if you like the style, it'll easily disappear into a pocket.