I am not trying to start any kind of flame-war, but working with various projects, I am often being asked about finding out possible inconsistencies, so let's look at CloneDVD now.
Starting an app, we clearly can see three sections and I will try to providey you my pov on what I would expect being logical:
1) DVD authoring - what would I expect here? Selection on DVD source (D, E drive, or even hd), ability to select chapters, audio streams and subtitles, all of them (select all), subtitles. The target - is it logical to have anything beyond DVD burner here? Maybe so, as I can write output to IFO or ISO, however that is the question, because - if I want to reauthor, I think that I expect to be ready to burn directly. If my intention is to first store ISO or IFO files, I prefer to decide later what will be part of DVD, so I always store full 9GB image. I would disable DVD Files and ISO buttons ...
2) DVD copy. Good old CloneCD, how clear it was - CD to image, image to CD, erase, CD to CD. So, DVD copy should be imo "one button" action, no further selection of what should be included, or what is DVD Authoring (option 1) good for then? Again - those two buttons are unnecessare here.
3) "Write existing data"? Existing where? On HD? Or on DVD drive? I think it was meant as write existing data from HD ISO or IFO files as source. But - why it let me to choose DVD drive as a source? And in that case, why it let me to choose DVD drive as a target, even if I have only one DVD drive available? What is more - IF it allows me to choose source of IFO/VOB from DVD drive, it SHOULD allow me first button option - DVD files, as I may want to transfer those files to HD and I can't here - I have to use option 1 or 2 to get IFO/VOB files to HD.
But let's say option 3 is good enough. I would change description of first radio button though, as it states "DVD" as a source, but it is not, it should say "IFO/VOB", as it is exactly that. The real room for simplification is in option 2 - DVD copy.
Just my opinion, I am realistic and know that it will not be probably changed, as it would mean some more radical changes to UI, but I could not resist