Co dot and antidot arrays with hexagonal symmetry have been prepared by combined electrochemical and sputtering techniques with significantly reduced nanoscale dimensions. Their magnetization reversal process has been analyzed on a macroscopic scale with Vibrating Sample Magnetometry (VSM) and on a microscopic scale by high spatial resolution Magnetic Transmission Soft X-ray Microscopy (MTXM). We observe for the antidot arrays a nucleation and propagation mode driven reversal mechanism induced by the in-plane anisotropy starting with nucleated clusters following the hexagonal configuration, and the magnetic hardness (i.e., coercivity) depending on the geometry parameters. Contrary, for arrays of short dots, a significant longitudinal anisotropy is deduced with large coercivity, where magnetostatic interactions gives rise to a more complex reversal process and significantly reduced remanence and susceptibility.