  While the simple picture of a spatially flat, matter plus cosmological
constant universe fits current observation of the accelerated expansion, strong
consideration has also been given to models with dynamical vacuum energy. We
examine the tradeoff of ``curving'' the vacuum but retaining spatial flatness,
vs. curving space but retaining the cosmological constant. These different
breakdowns in the simple picture could readily be distinguished by combined
high accuracy supernovae and cosmic microwave background distance measurements.
If we allow the uneasy situation of both breakdowns, the curvature can still be
measured to 1%, but at the price of degrading estimation of the equation of
state time variation by 60% or more, unless additional information (such as
weak lensing data or a tight matter density prior) is included.
