[chickkie]

For socks, I've tried DPNs for cuff down (which I can do no problem) Magic Loop for toe-up (so far, so good) but my next attempt is cuff down on twelve (12) inch circulars.

I am curious. Why did you try to use sixteen (16) inch circulars?
That length of needle is way too long to make socks successfully with. Personally, I would use sixteen inch long needles for hats but not socks.

I make a lot of socks, and I do toe up magic loop, 2 at a time with afterthought heels. I have tried to knit with those short circulars and they aren't worth the bother as far as I am concerned. I can do top down, have probably made hundreds of pairs of that style too, but toe up is my preference.