The new npm works great. The progress bar updates was only slowing it down on some platforms and has been fixed. The reason it has become slower is because it is flattening by default which everyone wanted and needed to happen.
However, having played with `ied`, it does flat deps and it's literally an order of magnitude faster (10-20x in my testing). I use npm a lot every day and npm's slowness is becoming a significant UX issue for me. I would like to continue using npm but right now I would switch if either `ied` or `pnpm` had decent feature parity with `npm install`.