Recently, I have been researching several CoreXY DIY designs for an upcoming 3D printer build. The primary advantages of CoreXY printers over Prusa-style Cartesian configurations are:
- The cubic enclosure provides additional rigidity
- The bed is stationary along both the X and Y axes (and sometimes Z). This allows the bed to be made thicker, heavier and more stable, and the print itself does not get flung at high speeds along the Y axis.
Keep in mind that there is nothing inherently wrong with Prusa kinematics, and they have been fine-tuned over the years to produce excellent results. But aside from the advantages listed above, a CoreXY might appeal to you just to build something fun and different, and learn new things along the way.