I recently switched to Sonic RecordDeluxe now and it's been very stable. I found out that Nero hasn't been consistently transferring my data files properly which resulted in my CD losing data. I would play an audio CD in my car and the music would skip and could barely play at times. No, it's not the CD (brand new), and it's not my car CD player (it's brand new).
I used Sonic and the problem was solved. I think I just had a bad batch, but Nero is a reliable company so no grudge against them.
Oh, they do everything Nero can do--even burn ISO images to DVDs as you mentioned.