I have a suspicion that for larger companies, it's more a question of which teams are like that than which companies are, since the line manager's attitude has a huge influence on the results (for example, one bent the HR system substantially for me to enable me to house hunt effectively - a personal act rather than an organisational one).

As for what percentage? I'm not really sure. Shadowcat is how it is because it was baked into the culture from day one because that's how things should be done, so I'm not sure I can extrapolate usefully from it.