The Verge: The Sony Xperia Z3 Compact features a 4.6-inch 1280×720 IPS LCD and is IP68 certified. The same 20.7MP image sensor in the Xperia Z3 is used. Instead of the curved aluminum frame on the larger Z3 the Z3 Compact sports a translucent plastic frame.
The Z3 Compact, contrary to its name, is a bit thicker than the flagship Z3: 8.6mm vs. 7.3mm, respectively. Vlad Savov seems to prefer the smaller size, plastic frame, and less pixels. I prefer the flagship Z3 with its larger size, aluminum frame, and more pixels.