Faster Backups or change Backup Media

General Discussion of backup speed of media. Unitrends.

Part of our Backup Strategy is to have a offline offsite backup of all media. These backups take a large amount of time (days). We have implemented compression and directly connected the Tape Library to the Backup Server. What other option can increase performance?

I see that RDX spec sheets can transfer up to 430 MB/s over USB 3.0. Does someone have a real world example of performance increase for RDX over Tape?

http://www.tandbergdata.com/us/index.cfm/products/removable-disk/rdx-quikstor/

http://www.quantum.com/products/removablediskdrives/rdx/index.aspx