I like metal and circular needles. But I often use bamboo circulars as well and love them.
I am yet to try with interchangable circs, I have been saving for a set... I think I will give Addi turbo a try. :$
I use circulars for everything, even flat knitting. Bought a full set of Chicagoos and Im in love. They are metal. I like the yarn to flow smoothly and I dont find that happens with bamboo.
I have a small set of sharp stainless steel Hiya Hiya interchangable circulars, but since I tried the ChiaGoo Red Lace stainless steel circulars, I love them and I regret that I have not decided for the ChiaGoo set when I bought my needle set. Although - or because - the tips are extremly pointed, I barely split the thread with the needle when knitting. I really enjoy knitting with the two ChiaGoos which I own so far and Im dreaming of a small ChiaGoo Twist Red Lace set now.