Compact system camera advice, confused

Currently using a nikon d40 and a Nikon 3100 dslr, looking to purchase a Csc but am confused which too buy! I have been looking at the Nikon 1 j1, the Panasonic llumix DMC g3 and the Sony nex c3. All roughly the same price. Any guidance or your reviews would be great. I'm after the basic functions of an slr without the bulkiness.
Btw I live in he uk for what difference it makes.
Cheers

Take a good look also at the Olympus OM-D E-M5

If you're used to zoom lenses, I'm afraid you're out of luck with CSCs. In order to reduce the size of the camera significantly from a D40/D3100 (which in itself is already very small), you will have to restrict yourself with the use of pancake prime lenses and a camera with LCD screen only.

Have you however considered the Canon G1X? It's not a system camera, however it does have a really good zoom range (what many people call "useful"), because of it's retracting lens design, it also comes out the same size as a CSC with a pancake lens, so all in all it may provide you with exactly what you're looking at.