We once more have no full-time managers at 37signals

This has a lot of appeal. I am instinctively wary of managers who can't do the actual job, which this obviously avoids. It also removes the 'management track', and presumably means you can see more progression as an IC (with a little bit of management). And I tend to agree major issues need to bubble up to leadership anyway.

Tangent but I am increasingly convinced the happiest company size maxes out around ~50 (give or take).