I have a SW-248B, and I like it thus far. I've upgraded the firmware to the latest version (R501). The firmware upgrade improves the media compatibility. It can write at 48x to the Verbatim DataLife Plus 48x, the FujiFilm 48x, and the Imation 48x CD-Rs.
I can tell you that (1) it is a lot quieter than my TDK VeloCD 48x24x48 and that (2) this burner can read and write to 99-minute CD-Rs.
Unfortunately, it does not
support Mt. Rainier (EasyWrite) at the moment. Then again, which 48x16x48 burner with an Oak Technology chipset (e.g., MSI, Optorite, Cyberdrive, CIS Arrgo) does?