  We present a performance analysis of compact monolithic optomechanical
inertial sensors that describes their key fundamental limits and overall
acceleration noise floor. Performance simulations for low frequency
gravity-sensitive inertial sensors show attainable acceleration noise floors of
the order of 10^-11 ms^-2/rtHz. Furthermore, from our performance models, we
determine the optimization criteria in our sensor designs, sensitivity, and
bandwidth trade space. We conducted characterization measurements of these
compact mechanical resonators, demonstrating mQ-products at levels of 250kg,
which highlight their exquisite acceleration sensitivity.
