I've heard that some keyboards are quieter without a PCB.
I'm working on my first hand wire myself (have the matrix wired - waiting for some parts to connect it to the teensy). It has definitely been A LOT more work than just going with a PCB.
I've been working on it on and off for a few weeks and I'm not done yet, whereas I can put together a PCB with LEDs in a couple of hours. I think it would be easier the second time, though.
Hopefully it's worth it in the end.
The nice thing about a hand wire is that you can do whatever you want with it, even if there isn't a PCB made. In my case, I'm redoing an old M0110, but a lot of people do it for slightly custom layouts that no one supports yet or for prototyping a new design.