@ Hag,
I have a Pioneer DVR-105 and a Sony DRU-500AX and have found both a quality product. The Pioneer DVR-105 is about ½ the cost of the Sony DRU-500AX. With the new Pioneer DVR-105 v1.30 RPC-1+2xDVD-R+12xRip Firmware I believe the Pioneer DVR-105 is better price value over the Sony DRU-500AX. The Sony DRU-500AX is more versatile in that in can record both the (-) minus and (+) plus media (DVD±R/RW) where as the Pioneer DVR-105 only records in the (-) minus media (DVD-R/RW).
Hope this provides information that will help you in your decision on which DVD burner to purchase.
Regards,
Coaster