By far the shiny satellite is worse. Besides, the satellites are tracked carefully by multiple parties, so any serious astronomical observation that could even

By far the shiny satellite is worse. Besides, the satellites are tracked carefully by multiple parties, so any serious astronomical observation that could even theoretically be sensitive to a sub-millisecond obscuration of a ~microradian portion of the sky (such as certain exoplanet searches) would be well aware of this ahead of time (and atmospheric aberration would be a far greater effect). A dark satellite is effectively irrelevant to optical ground astronomy.