  Masses of superheavy (SH) nuclei with $Z=98-128$, including odd and odd-odd
nuclei, are systematically calculated within the microscopic-macroscopic model
based on the deformed Woods-Saxon potential. Ground states are found by
minimizing energy over deformations and configurations. Pairing in odd
particle-number systems is treated either by blocking or by adding the BCS
energy of the odd quasiparticle. Three new parameters are introduced which may
be interpreted as the constant mean pairing energies for even-odd, odd-even and
odd-odd nuclei. They are adjusted by a fit to masses of heavy nuclei. Other
parameters of the model, fixed previously by fitting masses of even-even heavy
nuclei, are kept unchanged. With this adjustment, the masses of SH nuclei are
predicted and then used to calculate $\alpha$-decay energies to be compared to
known measured values. It turns out that the agreement between calculated
$Q_{\alpha}$ values with data in SH nuclei is better than in the region of the
mass fit. The model overestimates $Q_{\alpha}$ for $Z=111-113$. Ground state
(g.s.) configurations in some SH nuclei hint to a possible $\alpha$-decay
hindrance. The calculated configuration-preserving transition energies show
that in some cases this might explain discrepancies, but more data is needed to
explain the situation.
