I may have a chance to replace my good, but aging NEC 3500A with a new drive. NEC has done me well (have had both a 2500 and the 3500) and so far, I haven't seen a reason to switch away from them.
Currently I can easily obtain both the 3550A and the 4570A. I don't do any DVD-RAM writing currently, so that isn't an issue one way or the other. Most importantly, I want wide media compatibility, and I want good DVD AND CD writing quality. Read quality is less important, as my LiteOn drive is what I normally use for reading.
P.S. How is BenQ's newer drives like the 1650 stacking up with NEC these days?