The software only works correctly, intermittently. It seems that every time they issue a new release, either an old bug slips back in or a new one is created.
If you attempt to get support they request large amounts of information, basically using large amounts of your time (which costs you money), to debug their problems. Then, if you complain about the lack of stability in their product and their inability to provide software in which previously "fixed" bugs reappear, they either ban you from their support forum or delete your posts/ requests for help.
All-in-all the dvdfab "team" does not appear to be particularly competent or professional when it comes to development and support of commercial grade software. They appear to have no knowledge or use of modern software development tools and methods (e.g. revision control. unit testing, etc.). Their "support" team is arrogant, intolerant and dismissive of user complaints.
This is all topped off by their refusal to refund your payment for this mediocre and poorly supported amateur-grade software. I will not renew my subscription when it expires.
I would strongly recommend you not waste your money on dvdfab, unless you are a masochist or glutton for punishment.