Cabling between 2 TeraStations

[radioguru6613]

I'm probably going to look like a fool for asking this but there is something in the manual that's throwing me for a loop so I'm going to have to ask anyway. 

 

I have (2) 12tb TeraStations and in the manual it mentions something about using the Ethernet 2 port to link between the 2 of them. I'm currently running both co-located in the same rack using both ethernet ports back to my switch and configured in ATLB Port Trunking. 

 

I use both of the TeraStations for different things but I do run backups of certain shares from TS1 out to TS2 which is where I assume the advantage of the direct connection comes into play. 

 

I haven't experiemented with this alternate configuration but is there an advantage or dis-advantage to doing it with a link between the 2 units? 

 

Thanks!