  Do experiments based on superconducting loops segmented with Josephson
junctions (e.g., flux qubits) show macroscopic quantum behavior in the sense of
Schr\"odinger's cat example? Various arguments based on microscopic and
phenomenological models were recently adduced in this debate. We approach this
problem by adapting (to flux qubits) the framework of large-scale quantum
coherence, which was already successfully applied to spin ensembles and
photonic systems. We show that contemporary experiments might show quantum
coherence more than 100 times larger than experiments in the classical regime.
However, we argue that the often-used demonstration of an avoided crossing in
the energy spectrum is not sufficient to make a conclusion about the presence
of large-scale quantum coherence. Alternative, rigorous witnesses are proposed.
