Your best bet would be to contact Steadfast directly. Check out their contact info at http://steadfast.net/contact/. Regarding R1Soft, the product is good and their team has made a lot of progress and do a good job at maintaining it.
I'm wondering if anyone here is using Steadfast R1Soft CDP Backup for his servers and if it's truly working for him when a restore is needed and whether is causes a noticeable load or not?
Thank you for your interest in the R1Soft backup product. It's actually quite a nice piece of software. We have many customers using it and the feedback has been overwhelmingly positive.
Some of my own personal experience with it is that the initial backup that you first setup it usually quite intensive. I was seeing 30-40% CPU utilization during this time. However once you complete the initial disk safe it is relatively unnoticeable. I run 10 minute backups and usually see 1% CPU or less on the backup processes. It's a definite improvement over rsync.
Restoration is done through an easy to use interface, you can restore entire filesystems all the way down to individual files. So it gives you plenty of options. I can't say I have any experience with the barebones restore option in live environments however it seems to be a relatively easy process.
The only other feature I've used is the compression feature which reduced the size of my backup by about 40% which was really nice.
If you do have any further questions about it I would be happy to discuss it with you.
It really depends on what type of VPS your running. If your running a VPS based off vmware or Xen it might be possible to use R1Soft as you will be able to add the needed kernel modules. However if your using a virtuozzo based VPS solution Rsync would be the way to go.
The primary benefit of R1Soft over Rsync would be the way it backs up content as well as possibly reduced resource usage and the ability to backup the entire VPS. A rsync based backup would likely require more space depending on your retention policies such as weekly, monthly, daily, etc.
If I had the choice I would pretty much always go with R1Soft over rsync.
I have both Windows Virtuozzo and Linux Virtuozzo VPS...
Install the R1Soft CDP Agent on the physical machine where Linux Virtuozzo is installed.
Install the R1Soft CDP Agent inside individual Windows Virtuozzo Containers.
Some users install the R1Soft CDP Agent on the Windows Virtuozzo Physical server. This is ok... be aware this depends on the Virtuozzo Volume Shadow Copy Writer which fails if there is a disabled Windows VPS container.