I struggled to get through it, honestly. I found the first act slow—it spends a lot of time establishing the parents' past and the experimental program before the titular 'firestarter' aspect fully kicks in. For a thriller, that opening drags. Once Charlie's abilities manifest, it picks up, but the tension feels uneven compared to other King works like 'Misery' or 'The Shining'. The Shop, as the antagonist organization, is a bit cartoonishly evil for my taste. I wouldn't call it a must-read for thriller purists; it's more of a slow-burn supernatural drama with thriller elements in the second half. The father-daughter dynamic is the core, so if that appeals more than relentless pacing, you might like it. I finished it, but it's not one I'd revisit.
That said, the audiobook narration by Dennis Boutsikaris is excellent. He captures the dread and the childish innocence of Charlie really well, which elevated the experience for me. I'd recommend that format if you're determined to give it a try.