Roxio is a idiot proof package (sorry for idiot part, no offence, but it is really easy to use). The only thing I do not really like is it installs too many things on PC.
Nero is rather clean, you can install just the component you want and uninstall is also very clean. But it is not as idiot-proof as Roxio, i.e. it is powerful package, only need a little learning to get best out of it.
There are some good functions with nero, but you need to pay extra if you want to convert music CD into mp3 files because mp3 encorder is not included in the package. Roxio's function of converting cd to mp3 is great and easy to use.
You can download a full working version of nero to test out click here
Used Nero for years. Takes a few sessions to get used to but is very easy to use after that. If buying new, I would assume that Nero 6 has usefull features such as InCD (Formats CDRW's to use as giant floppies) very usefull indeed. Just my humble opinion!
i would recommend nero because of the flexibility and extras that will become more important if your needs expand over time. as basic burner software there is no real difference i.e speed/reliability/ quality of finished product etc. however nero may not be compatible with quite as many burners and does seem to cause conflict with windows own burner software(roxio).