  A detailed compilation of uncertainties in the MSbar bottom quark mass
m_b(m_b) obtained from low-n spectral sum rules at order alpha_s^2 is given
including charm mass effects and secondary b production. The experimental
continuum region above 11.1 GeV is treated conservatively. An inconsistency of
the PDG averages for the electronic partial widths of Upsilon(4S) and
Upsilon(5S) is pointed out. From our analysis we obtain m_b(m_b)=4.20\pm 0.09
GeV. The impact of future CLEO data is discussed.
