No, not the puzzles..(!)
I've always thought jigsaws had pretty limited applications, mostly cuting shapes in thin sheet materials, and rarely use them otherwise.
Today, I was watching a Youtube video on levelling floors and the (apparent, but seemed to know what he was about,) pro doing it used a jigsaw to cut notches in 2-inch joists. None of the ones I've owned (all cheap and cheerful, not pro tools) would be capable of doing that without wandering about 30 degrees off vertical.
So should I be thinking about getting a decent jigsaw or am I using them wrong?