I agree about the WD not-so-smart software - I hate that I have to download software to disable (not delete) that stuff. That's why I suggest you go for the GoFlex desktop unit from Seagate. They are available in several interfaces, including USB3.
One thought - if you can use smaller drives, another option is a pair of 1.5TB GoFlex 2.5" drives. They have the advantage of not requiring a wall-wart, so they can be used anywhere or anywhen