I have had a Sony DRU500a for about a year. It has been to Sony for repair once. Generally it has been a good drive for DVD+ and -R media but totally inconsistent with RW media.
Received my new NEC ND-2500a on Thursday. It was Dec 2003 manufacture with firmware 1.05. Updated to 1.06 first thing. I have burned several (Costco) TDK DVD 4X at 6X using Nero 6.3.03. It even reads DVD+RW that my Sony would not!
Very pleased so far! Highly recommended.