in 2011 I have an eSATA/USB 2.0 (single and dual bays) unit that have 2TB max size - Note: dual bays - only one works with eSATA connection (notebook has to offer 2 addresses for both bays to work, why I purchased single bay too).
in 2014 I purchased the USB 3.0 dual bay model, and these do not have max size. I have two 4TB drives in this unit providing 8TB's (2 drive letters) of storage for my Notebook (recording HD TV shows).
After looking at the link you provided I could not say 100% which unit you are looking. It says USB (but not if 2.0 or 3.0) I tried to see if 5G was in the name (I purchased the first white (Snow edition) 5G models in 2014 that were USB 3.0.) Best Buy pictures do not show the ports available (you do not want the model with an eSATA port).
Now new models are Back like the USB 2.0/eSATA models with 2TB limit, so no help there.
Most likely these are the USB 3.0 models (there is nothing about eSATA interface pointing to the newer unit too).
The units I saw (Aug 2016) in stock at Billings, MT store were the USB 3.0 models (wanted).
http://th.thermaltake.com/products-model.aspx?id=C_00001950
It is odd that the black 5G model shows 2TB max size while 5G Snow Edition has no max size noted. I do not know what to tell you. I had no issue with the snow edition with 4TB drives. Maybe the original text was written (about 2008) when 2TB was the max size offered on the market and not really a limit.