sony rx100 worth buying/ £430.00 is it a good compact?

will it take better pics/video then the hx20v which is half the price... and how is the picture/video quality compared to the nex-7

i want something portable, but for the same price you can get an slr... i will be mainly taking family pictures.. what would you say would be the biggest print size that will be acceptable on the rx100? i may want to print out some canvases etc