I'll go ahead and post my results in this thread. I used Nero 7 Ultra Edition Enhanced v. 7.10.1 to burn my CNDV-80MT 2008 update discs successfully at 2.4X (that's the default slowest my burner will do). Equipment was a Dual Layer capable Dell CD/DVD +-RW drive (Dell P/N C3284-A00) in a Latitude D610 running Windows Xp SP3. I didn't want to mess with doing it on Vista so I did it on one of my laptops that had Xp. The computer I did it in was equipped with the 2.0 GHz Pentium M processor and 2 GB of RAM. The discs were Sony DVD+R DL. They ran me about $22 at Best Buy for a pack of 10. The first disc I burned was the East one and it ran fine. Took a total of 1.5 hours to burn it with data verification in Nero. When I did the West disc, it failed verification on a small number of tracks, but all was well when I stuck it in the unit (Avic D3). I'm running a second copy now to see if it passes verification.
I should state that I purchased the discs from Pioneer for my parents N4 I'm installing for them over the Thanksgiving holiday. I used the actual Pioneer East disc for my initial update of the unit to ensure that nothing went wrong. I then swapped out the disc with the copied East disc and it was fine. I'm sure it would've been fine using the copied discs for the initial, but after the posts I read in the torrent threads on here, I wasn't going to take any chances.
On a side note, the update itself only wiped out the custom background screen I had on the unit, the custom splash screen at start up I have stayed in tact.