Hi,
I've now tried it on an 'old' Gigabyte mo'bo with 2 inbuilt Sata drives, installed with no problems.
Also tried it on a Dell SC1435 server with to SAS drives, installed with no problems, (it's now running on the same server using the 2 built-in Sata ports).
The ability to hide folders is a good idea and you should move it to the 'Suggestions' section of this site.
Never had any problems using a machine while it's being backed up, but I see it could be a problem in some cases. I guess the answer is to schedule the backups outside the normal usage times. I think the pause, is a great idea, plus a resume feature if the network connection is lost, (eg wireless).
Apart from the initial backup, it already only backs up disk sections that have changed and I find it only takes a few minutes for most machines.
However, as I said, redo your suggestions in the 'Suggestions' section.
Colin