DCK; is a black box imager for good drives only similar to what you could do with just about any software imager for your computer. Just in a portable more expensive and convenient solution. I'm not sure why someone would need this unless they wanted to image a drive while on the bus.
UDMA; is an expensive professional tool used for data recovery. Been around for many years. Accepted by many as one of the best solutions for recovery of failing hard drives. Notice that I said one of the best because there are other tools out there that are cheaper and can more or less do the same thing.
If a person happened, stay with me, happened, to have both a UDMA and DCK they would probably use the DCK to anchor their boat.
