Corsair's VX450W is exactly the size of a standard ATX power supply, so it is guaranteed to fit all cases.
The back of the PSU has low airflow restriction thanks to the stamped holes. A power switch is there to completely turn the unit off.
The surface of the VX450W is a bit grainy and rough. This means that the unit will not take any fingerprints and also makes it it more scratch resistant than those highly polished glossy PSUs.
A single slow running fan ensures that your PSU stays cool.
A modularity feature is not present. Nowadays most manufacturers add this convenience feature, on the other hand it may add a few dollars price premium that many people are not willing to pay for a 450W PSU.
The extra four pins of the 24 pin ATX connectors can be detached on one side, but not completely removed. If you run into space issues on your motherboard, just cut through the thin plastic.
Two seperate cables are available to be used for the 4-pin or 8-pin 12V motherboard socket.