Optical/infrared interferometers provide some of the highest spatial resolutions available in astronomy, but obtaining model-independent images is often complicated by sparse uv coverage, and/or changes in target appearance due to source variability while the uv plane is being filled. In this contribution, we show the limitations of the current four-telescope second generation interferometric instruments at the VLTI based on previous experience, and quantitatively consider the solutions offered by utilizing all six available delay lines of the VLTI simultaneously for a six-telescope beam combiner instrument