I think it's pretty popular for cloning raspberry pi SD cards. It has a feature where you can stick a bunch of USB SD card peripherals and program multiple cards at the same time. Honestly most people don't care too much about the image size or performance I think it's more that when you use it you are pretty certain that you are writing the correct target drive. I've done it may times with dd command and every time I am nervous about overwriting my os drive.