We use R1soft both within our PoPs and to replicate data, for some customers that need offsite backups from our NL PoP to our German PoP. It works, but it needed a little tweaking. It looks like R1soft build their software mainly with local backup in mind.
I am not sure what the performance impact will be over a even larger distance, like for example Germany - USA like you mentioned.
On a side note:
We use the software to write changes every 5 minutes. You plan to store a backup one time a day. That should be no problem.