I have the LiteOn 40x (LTR-40125S). The box says CenDyne Lightning III, but in the box its a LiteOn with sticker to prove it. Believe it or not, I returned a Plex 40x (401232A) to get this drive (which is actually an excellent drive).
The LiteOn 32x has reviewed fairly well, but the 40x is pretty much considered to be the best burner currently out there (do a Google search and you will see what I mean). It has fantastic DAE, is very compatable with media, burns reliably at 40x, and best of all can burn Safedisc 2 v2.51.021...a CD protection that almost every other burner has problems with.
The only bad thing about this drive is that the CD tray is a little flimsy when fully open. The Plex has a solid tray, BTW. But the LiteOn outperforms the Plex in almost every test...so I will trade a slightly flimsy tray for performance any day! Besides the LiteOn is $40 cheaper.