  We discuss the evolution from BCS to BEC superfluids in the presence of
spin-orbit coupling, and show that this evolution is just a crossover in the
balanced case. The dependence of several thermodynamic properties, such as the
chemical potential, order parameter, pressure, entropy, isothermal
compressibility and spin susceptibility tensor on the spin-orbit coupling and
interaction parameter at low temperatures are analyzed. We studied both the
case of equal Rashba and Dresselhaus (ERD) and the Rashba-only (RO) spin-orbit
coupling. Comparisons between the two cases reveal several striking differences
in the corresponding thermodynamic quantities. Finally we propose measuring the
spin susceptibility as a means to detect the spin-orbit coupling effect.
