I knit my socks with dpn, always have ans still do. One at a time.
the 2 circs method sounds good to me, though, and I agree on magic loop: it is possible but it is not mine, really.
advantage of 2 circs: less needles, less risk of dropping one out, less needle changes, I have not done it, but it sounds good.
What I have done for hats when they get to small around for my circs: put one section on a dpn, work the rest off the circ. (I just did not own enough circs in equal sizes, but that just changed rapidly)
I used to knit all socks bottom down and was happy with it.
Lately I learned the diagonal heel with sort rows and LOVE LOVE LOVE it! I will do this as my prefered heel forever, I guess. It's easy, it is quick, no holes, no ridges, no fuzzing, no calculation.... all really easy. And it works toe up and bottom down.
Lately I got the book by Wendy D Johnson about toe up socks. So I just knit my first one. It is fun, really.
What are the differences?
Heels form differently, therefore some may prefer one way, some the other. With the diagonal heel: either way the same.
Directional patterns (lace in some cases, traveling ridges and such, for example) run either up or down...
When - as usual - you have no unlimited resource of yarn of one type, you can still make your sock as long as possible, because all that may be longer or shorter is the leg and not a missing tip or anything - when you work toe up.
you can try on toe up socks on the foot - and THAT is where a sock needs to fit best. If something is wrong, you do not have to undo so much (but I only ever undid the foot section, anyways, for fit).
My socks usually have a pattern only above the ankle, so that they fit into shoes if needed and do not rub me sore.
If you do that, it may be helpful to work the pattern section first of all (cuff down) and then have "mindless knitting away" for the rest. That seems to be a quicker finish for me.
My usual method is cuff down, but there are advantages for toe up. So I guess this is all just a matter of taste. I am happy I know both ways now and have learned a few new tricks along the way. Whatever I do with this in the future: trying both was a step ahead for me.
Have fun with socks.