Concerning the promotion thing, I hear this a lot from Googlers but isn't it the same everywhere else? Most tech companies (big tech at least) will promote on product achievements, not maintenance.
This does help in various ways – the process is more objective, there is less bias, less departmental/managerial politics etc. The drawback is that a lot gets lost in translation. There is too much burden on you as an engineer to pick and choose what you spend your time on so it looks good to the committee.
In other companies I have worked at getting promoted was a byproduct of doing a good job. At Google getting promoted is the job.