different orbit distributions depending on whether they are based on 2D spectroscopic data or 1D long-slit data. Without a DM halo, instead, the difference between models fit to IFU data and models fit to long-slit data is less significant (Figure \[fig:nodm\]); if anything, models fit using IFU data are slightly more radially anisotropic. This indicates that IFU data are important for the recovery of the orbital structure, because they help to constrain the gravitational potential, in particular the mass of the central SMBH more tightly. In @Rusli13a, we find that SMBH masses change on average by a factor of $\sim 2$ when including a DM halo; in a similar study, although based on 1D [[*HST*]{}]{} data, @Schulze11 find an increase in SMBH masses of only $\sim 20$%.

We conclude that a reliable reconstruction of the central orbital structure requires the [*combination*]{} of IFU data and DM halos in the models; neither factor by itself is sufficient.

Uncertainties
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Almost all previous works – and ours – assume axial symmetry for the studied galaxies. The only published triaxial models, for the centers of NGC3379 and NGC3998 [@vandenBosch10; @Walsh12], are dominated by box orbits in the innermost regions. Box orbits do not 