Definitely no reason here to upgrade. I have tested it, though not deeply, and won't be installing it on my main PC.
It should say volumes to the developers that somebody who can install it (for free don't forget ), won't be. In fact, it looks as if I'll be uninstalling it on the PCs that I've used for testing.
My main problem with Nero is with Vision Express. All versions later than 220.127.116.11 have really long encoding times.
Trouble is that other programs, like Roxio, don't allow too much configuration, seemingly being designed for n00bs (which is fine).