That sounds like file versioning. I agree it is useful to allow recovery of accidentally deleted or corrupted files.
Yes. We all make mistakes and having some protection against the damage they can cause is important.
I made mistakes in looking after my own data. In my case it was moving my laptop and in the process dropping my connected USB drive to the floor breaking it. Then to make matters worse I didn't backup my laptop for a while and the hard drive in my laptop failed.
Then in 2009 I bought my first NAS and now I have several.
As an option, NETGEAR NASes support unlimited volume snapshots, as well as Time Machine and very flexible backup features both to and from clients and other NASes.
From what I've heard over the years very flexible backup features is one of the ReadyNAS's key strengths. Where possible running a backup job on the faster device can help with the performance of running backup jobs. Or you may want the flexibility of configuring all the backup jobs on the one device so you can keep track of them easily.
No matter what device you choose, whichever brand it is, if it stores the primary copy of important data it needs to be backed up.
Features that protect against accidental file deletion, data corruption etc. will help to reduce the likelihood of needing to restore from backup, but backups are still important. I can't stress this enough.
There are problems such as multiple disk failures (more than the RAID level you are using can handle), other hardware issues, filesystem issues, fire, flood, theft etc. that no single device can protect you against.
Having called Netgear's "Professional Product" customer support, and been subjected to the worse that Bangalore can offer, I take a pass on Netgear pro products except for switches which just work.
You may be interested to hear that our support offerings have changed recently.
There's now an online chat alternative to making a phone call, which you may find works better for you.