The knowledge 79 couple of hundred will sound OK with your speakers in a small room but it probably won't last too long if gigged hard. If it has a bit of abuse it might just fail and take the speakers with it. Rental companies can't take that chance. Recent trends and advances in technology have seen the great big old speaker boxes and amplifiers replaced by much smaller and more manageable units that have higher efficiency and can provide better sound in smaller packages. This is good for everyone concerned, especially anyone who has to carry it.