Front Accessible Switchgear can save owners a lot of money:

You can reduce the amount of space required in your electrical equipment room by 60% by purchasing front accessible switchgear. In addition, this will substantially increase the safety and maintenance factor. Circuit breakers can be purchased at lower prices because each breaker will be 100% rated (not de-rated as ANSI suggests) and installation of cables will be substantially reduced because they will be in a dedicated space; not tangled up with other circuits