My take on Google's hiring process, having observed a few people going through it, is that it's a complete nightmare. Unfortunately I don't think there's any incentive for them to change because so many people are willing to go through that nightmare in order to work there.
My whole approach to recruitment is to strip the process down as much as possible to make it as easy and appealing as possible for people to apply, but that's because I have to: I work for a company nobody's heard of, and which doesn't have engineers queuing up to work for them.
In my experience, the recruiters are some of the best, nicest folks I've had the pleasure of dealing with. I know that's a low bar to crawl over in the world of copy-paste recruiters, but they were good folks who made sure things worked, and when my interviewer failed to call, made sure to prod his ass.
Now, I didn't get past the phone screen but the experience actually interviewing was so piss-poor I doubt I'd have pressed on had I passed. The interviewer managed to call nearly 30 minutes late, spent about as much time talking about himself as he did asking me questions, and when he actually asked questions he would proceed to repeat what I had said as if I hadn't even said anything.
My whole approach to recruitment is to strip the process down as much as possible to make it as easy and appealing as possible for people to apply, but that's because I have to: I work for a company nobody's heard of, and which doesn't have engineers queuing up to work for them.