Before my BSA hotspark, I had an SOS firestarter (ferrocerium rod embedded in a block of pitchwood). It worked great, and I got addicted to it, practicing going from spark to flame for any reason at all, even before brushing my teeth in the morning (at home!). Finally grew out of that phase (well, sorta….).
The problem I encountered was that I started off using full strokes along the sparking rod, and this caused a little bit of a gouge to develop in the middle of the rod, eventually causing my striker to 'snag' before it got to the bottom of the rod where my tinder was, making my firestarting attempts a little more problematic. This wasn’t a flaw of the product, just in my initial technique in using it. So this bit of advice is - don't start your sparking strokes from the top of the sparking rod. Start pretty close to the bottom of the rod, and press down with a short, slow & firm stroke. The sparks will be plenty, it will limit your tendency to ‘smother’ your sparks/tinder, the sparks will land much more accurately on your tinder, and you won't ruin your firstarter’s rod by gouging it in the middle.
Also, I'd recommend replacing the striker included with most firestarters with a short bit of hacksaw blade. I never cared for the striker that the BSA Hotspark came with, and that tiny bit of chopped-off hacksaw blade I swapped it out with gives a better shower of sparks. I'd really avoid using a knife blade as a scraper (hacksaw blades are cheaper and lighter). You can also drill holes in your hacksaw blade if you're that desperate to save grams.
And of course, there’s the cost savings. I bought 4 of the BSA hotsparks for $10, so I’ve always got one with me.