The RX10 is a bridge camera features a 20.2 megapixel 1.0-type back-illuminated CMOS imager and a 24-200mm (eq.) f/2.8 OSS lens.
Sony Drops Price of Cyber-shot DSC-RX10 Bridge Camera
Panasonic has announced the 1″-type sensor Lumix DMC-FZ1000 superzoom bridge camera and features a 20.1 megapixel 1-inch MOS sensor, 16x optical zoom lens which has an F2.8-4.0 aperture range, 0.09 second auto-focusing speed, a 2,359k OLED Live View Finder (LVF) and a 3-inch 921-K dot LCD display.
Panasonic FZ1000 is a definite competitor against the Sony RX10 with a more useful 25-400mm lens range and 4k video recording. See Panasonic FZ1000 vs Sony RX10 Specifications Comparison here.