I have three drives for burning and I would make two suggestions. As you probably cannot get an NEC 3500 anymore, my LG works almost as well as the NEC and turns out very good results on any of the media I list below.
As to your problem with -RW; it is generally considered to be crap and the samples I have tried proved this. Many other users have reported the same. Avoid it at all costs and stick with +RW. The only one I have ever seen that was decent was a 4X -RW from JVC and I have never seen it for sale.
I would avoid the BenQ. It is VERY picky and doesn't do a decent job on any of my media other than the R03.
See here for scans: