Hardware hard disk encryption vs Software solution ?

Did anybody have experience with hardware disk encryption devices ? What is better to use at home ? Some hardware solutions are cheaper then software but I am not sure if they really are so fast and problem free. I always had problems with software encryption. I have found a product described here http://www.elkom.com.tw/?section=2 but I don’t believe that it is so fast as manufacturer says. The price is suspiciously low as for the strength of the encryption. There are plenty of other such devices out there.
Please advice.

Tom.