Well in my case I've been using Nero from V 5 till V 7 Ultra, It always had the friendly interface and burn verification etc etc..
But when I switched to DB Pro it only took almost 20Mb while Nero always took greater than 300Mb HD space.
Some features in DB were comparatively quite slow,got some incompatibilities with my samsung DVD burner,DVD erase function works fine until some other application shows it's not erased.
But it worked fine with no other problem.
Couple of days back I got to read a thread in DB forum that DB lacks burn verification feature.I'm not sure it's true but if it is.. then it's a serious problem.
Other than that it has stimulate option which shows a simulation before burning which ensures burn process won't go wrong while burning. This feature is pretty unique fr DB.And it supports creation of ISOs.So I still like it.