I tried more than one of the copying/backup tools, Gs richcopy 360 is one of the best because of the below reasons:
-powerful in copying Larg files
-works fine over LANs and over WANs
-optimized for WAN and Internet Replication
-long path names support
-can sync Data Real-Time
-auto Update Features
-run as a service
-copy only modified files
-copy NTFS security
this product is highly recommended