The XC10's dimensions are 4.9 by 4.0 by 4.8 inches (124.5x101.6x121.9mm) and it weighs about 2.3 pounds (1 kg). That makes it smaller than a Panasonic Lumix DMC-GH4 with an equivalent lens on it, but not necessarily lighter. The viewfinder, which mounts onto the LCD, is optional.
The XC10 bears a lot of resemblance to a megazoom, with its fixed 24.1-241 (still), 23.7-237mm (video) manual-zoom lens. While the lens starts at a fast f2.8 maximum aperture, by the end of the range it's f5.6 maximum.