I used this implementation to rescue the data and OS from an old and low performance machine (PIII Xeon). The installed HDD wasn't that big, so dd was a good choice for the time being. The server in cause was a simple 1U old HP server, with a pretty small HDD (I don't recall its size anymore). I guess there are lot's of people out there that want to get rid of the old hardware, and to keep the valuable data along with OS. For this purpose, the described method is the way to do it. But there's always room for improvement....