Got the Pioneer DVR-108.
Got a 5-pack of Fujifilms 4X (media code ProdiscS03).
Got a DVD-Video backup, burned at 2x with Nero 220.127.116.11 (patched against incompatibility with Windows XP SP2).
Result: DVD is playable only in the burner. After about 30 retries on my LG DRD-8160B I was finally able to get it to recognize the disk and do a test with Nero CD/DVD Speed. Here is the result: