I learned to knit socks using magic loop -- I learned from a booklet I purchased from a LYS. However, for my next sock pattern I went to DPNS because so many patterns are written that way. I picked up the book, Sensational Knitted Socks (highly recommend it, BTW!), and they have directions for DPNS and 2 circs. For Xmas, I rec'd Cat Bordhi's book, Socks Soar on 2 Circs, and was planning on purchasing Knit Picks circs to try that method. The Knit Picks circs are very inexpensive -- around $5 each, I believe. I have heard people say that it is easier to get ladders when using 2 circs, but I really like the idea of being able to try on your sock as you go!
Now that I've done more than one sock, I'm starting to better understand sock construction and I think I could more easily understand using magic loop w/ a pattern not written specifically for magic loop. I really don't mind DPNS (I use wood), but I'd like to compare using 2 circs and see if it really is much faster. I don't know that I was faster using magic loop over DPNS, but it was my first sock project.