You can always make your own performance measurements.
"Set HSL" sounds like a third-party effect (Construct only has "Adjust HSL"); in both cases the effect runs entirely on the GPU, and they're very good at it, so it will probably be hard to measure a difference either way. The only real difference is any shader using HSL will have to perform HSL-to-RGB conversion at some point, which takes quite a lot of calculations, but the architecture of GPUs generally means they spend so much time waiting for memory access that there's a lot of time to spend doing calculations, so it probably still doesn't make much difference. I guess it might save a bit of power.