The manipulation of the velocity of optical pulses in fibers by so-called slow-light systems seems to be very promising for future all-optical networks, but actual approaches suffer from an inevitable pulse broadening due to the delay process. In this article two different methods for the achievement of zero-broadening in Brillouin based slow-light systems are compared in theory and experiment. While one system works in the saturated regime of a Brillouin amplifier the other works in its linear regime. Both approaches fully avoid the system inherent broadening of conventional slow-light delays and can therefore extend such systems to increase their efficiency significantly.