Which size circs would I get more use out of?
What weight of yarn are you calling 4 ply? How many wpi?
It depends on how tightly you knit and the guage of the pattern. I’ve knit up to 3 sizes smaller and 3 sizes bigger than patterns suggested, so I’d probably say you should get all 3 if you’re going to be using 4 ply yarns a lot. (Or, you could do what I’ve done in the past and take 3 different trips to the yarn store until you find the right size needles for that particular project.)
It depends what you’re going to make with the yarn - socks, mittens, sweaters… It depends on your gauge and the gauge of the pattern. I have multiple needles in all sizes from 8/5mm to 17/12mm, because that is the range I knit on lace or bulky yarn. I use 10/6mm to 7mm most of the time.
I’ve taken the plunge and gone for the 2.75mm. I’m sure I’ve got the other sizes somewhere or other but I’m ordering a harmony circ and want a size I can use lots! Plus I want to use it with my new hat pattern from the yarn swap and some sock yarn I treated myself to.
Thanks for the replies anyway