File>Options>Standard Tests>Lower right hand corner use selected write speed and pick which speed you want to use or you can stick with the maximum
Then (File>Options>Standard Tests still)>Transfer Rate>Lower right hand corner check the circle for data and check the circle for burn image file and include test data
Now when you select Create Data Disk (F9) in run tests, it will prompt you to choose a file for burning. This way you can still get a usable disk out of what you burn.
I learned this from some post on this board somewhere. I forgot who wrote it or I would give credit.
FWIW, I have never had a problem with DL discs created with decrypter.
Also, burn image is ther in plain sight in Nero Express. I never really looked at that as I was always trying to do it from the dvd-video section. I am going to try and burn an ISO file DL dvd with Nero burn image option to see if it can compare to decrypter.