BackWPup/BackWPup Pro was one of the most reliable and trustworthy WP plugins as of version 2.x. I have used it myself, recommended it and installed it on 4 of my clients.
If there was a plugin I would pay for and tell my clients to pay for it would have been BackWPup/BackWPup Pro as cost effective insurance for their business. It was just a no brainer. In my 4 customers sites it has gone in on my recommendation.
I am not sure if the versions past 2.x have been pushed into a release without rigorous testing just to get some money in from the Pro version or the team just didn't understand the finer points of the code. All I see is the results.
Amongst the many issues I have set the the "To: Files" "Number of files to keep in folder." to a specific number that BackWPup/BackWPup PRO now just ignores. I have used this in previous versions with great success. Now it looks like the default value cant be overridden from the gui. This gives the effect that all disk space is used by huge numbers of un-nessessary backup copies. Causing mail to fail, great for an e-commerce site and the the sites to fail or be drawn up in an uggly way.
This has caused my clients disruption to their business sites, anger and frustration. OUCH!!!!
To have to wright this type of review is a real waste of life.
If BackWPup/BackWPup Pro were s wine I would NOT recommend that it be laid away for further development and maturation. It should just be laid down and forgotten.
Especially if you need a solution you, yours and your business needs to trust and depend on.