Quasiclassical trajectories have been used to investigate the heavy-light-heavy ion-molecule reaction, O- + HF --> OH + F-, using approximate potential energy surfaces. Multiple surface effects are neglected. 1D and 3D dynamics on the same surface produce very different vibrational distributions. OH product vibrational distributions are relatively insensitive to details of the potential. Product rotational energy distributions, on the other hand, are quite sensitive to features of the potential surface, particularly the steepness of the bend. Long-range ion-dipole forces play an important role in the dynamics, particularly in the angular distributions. Product vibrational energy and angular distributions are compared to two sets of experiments.