Should I buy an Essentials or a MyBook?

I have two WD external hard disc drives and need a third. I have a WD MY Book and the other is a WD Essentials.  I want to buy a 2TB external drive to add to the two WD drives I have now. The new drive I will buy will be used on a Windows 7 PC NOT on a network to be used by a single user. I do not care if it is USB 3 or USB 2. It will NOT be used to automatically back up. It will just hold my files that I put on it manually. I don’t know the difference between the My Book series and the Essentials series enough to know what one to order. Both are the same price right now and several places have good deals on both series now. Is there a reason I should go for the My Book series versus the Essentials series, or vice versa? 

Another question: I am out of extra USB ports. Can I use a USB splitter with external hard drives to plug two external drives into the same USB port? Do you where I might find one of these?

Many thanks, barnkeeper10

The Elements is a simple plug and play drive with no software, no password capability and no hardware encryption. It is not recommended to use a hub or USB cable longer than the one provided.

Joe