I don't have any experiences with Asus CDRW drives, but a colleague of mine (now sitting next to me) does.
Here's what he says:
My Asus 48x drive works very well. I burned over 2000 CDRs already and didn't have any problems, even when burning more than 200 discs in a row. I didn't test it with copy protected discs, but concluding from what I've read, the drive should perform quite good at this point.
I've been using a LiteOn drive since about 9 months now. Although I have the 48x24x48x instead of the 52x model, I can tell you that LiteOn isn't a bad choice at all. It handles most copy protections really well, isn't picky with media, comes with Nero and has very good writing results (read the reviews, they can tell you more..!)...