I've been using Fiasp since May (I'm on the pump).
I find it a lot better than Novorapid. Corrections work more quickly and spikes after food are much smaller.
I thought I was going to have to raise my doses, as others had, but the increases I had to make in May/early June had to be reduced at the end of July, so my total daily dose is about the same as it was when I started Fiasp.