I just tried the Nanostriker today along with a few bigger firesteels (a swedish steel, a strikeforce) and a few others, and considering that I'm years out of practice, I had the most luck with the Nanostriker. Took me a few minutes to figure out why ... I used the supplied strikers with each of the respective steels, and since the Nanostriker's striker is well sharper than most stock strikers, I was getting just as much sparks from the little guy. It also seemed easy to aim, and that helped. Anyway, once I switched to using my knife on the bigger steels, that changed the equation. But I'm very confident in the Nanostriker on any kind of good tinder like Tinderquik.
I, too, would love to see a misch metal steel included, and a variety of tinders including (as mentioned earlier in the thread) perhaps a few tinders that aren't so easy to light. I wonder if, for example, the misch metal steels will light those tinders when the ferrocerium won't.