  We present two variants of a magnetic microcalorimeter with paramagnetic
temperature sensors and integrated dc-SQUID readout for high-resolution X-ray
emission spectroscopy. Each variant employs two overhanging gold absorbers with
a sensitive area of 150$\mu$m x 150$\mu$m and a thickness of 3$\mu$m, thus
providing a quantum efficiency of 98% for photons up to 5keV and 50% for
photons up to 10keV. The first variant turned out to be fully operational, but,
at the same time, to suffer from Joule power dissipation of the Josephson
junction shunt resistors, athermal phonon loss, and slew rate limitations of
the overall setup. Overall, it only achieved an energy resolution $\Delta
E_\mathrm{FWHM} = 8.9eV$. In the second variant, we introduced an innovative
`tetrapod absorber geometry' as well as a membrane-technique for protecting the
temperature sensors against the power dissipation of the shunt resistors. By
this, the second variant achieves an outstanding energy resolution of $\Delta
E_\mathrm{FWHM} =1.25(18)eV$ and hence provides, to our knowledge, the present
best energy resolving power $E/\Delta E_\mathrm{FWHM}$ among all existing
energy-dispersive detectors for soft and tender X-rays.
