Your hard disk will run hot in a dock, not good for long use.
Well, it's good for certain set ups... and how did you know if he is going to be using it for 'long use'.
To TS:
I am using the cheapest one I can find, which is a 1 bay dock from Astone, from Laser (SLS). USB 3.0
I also have an old Nexstar one (USB 2.0, esata). Both of which are still working because I don't use them for 'long use'. Which makes them recommendations, I guess.
