To me the 90 degree spine issue is kind of "meh". It's nice to strike a firesteel but most of the 'steels I carry have dedicated strikers (my favorite being the GobSpark Armageddon by Firesteel.com). Perhaps the bigger reason for that feature is to scrape wood to make very fine tinder. Great if you do it that way but that's not my usual technique.
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“I'd rather have questions that cannot be answered than answers that can't be questioned.” —Richard Feynman