I interviewed at Amazon and it was fine. The questions were interesting (albeit maybe a few too many graph questions). One of the interviewers showed up in a bathrobe or something I think, due to a bad oncall the previous night or something.

Given that Amazon interviews by team, I think it depends on what team you end up interviewing with...

I didn't take the offer because it was like $20k or more less than another offer, but the process was fine.

There's also going to be selection bias, in that most people who have reasonable interview process aren't going to write blog posts about it...