Excellent grip and feel!

The feature set is very similar to the E-420, but for the extra dough you do get some significant capabilities, such as sensor-shift stabilization (including an updated system with a mode that accommodates panning while vertically oriented), a larger continuous-shooting buffer and a deeper grip.
Like the E-420, the E-520 incorporates the same sensor as in the higher-end E-3. It also seems to use the same viewfinder and LCD as its little brother, and also includes support for face detection (still unusual for a dSLR), wireless flash and tonal-range correcting Shadow Adjustment Technology.