My go-to
I do everything on a circular needle, even if it's flat, for two reasons: first of all you can't drop your other needle (and I'm disabled, so it could be awkward if I did), and secondly it's just so much more compact than using straight needles. You can knit in a hospital waiting room and you're not going to poke anyone. So I use these all the time, and they're wonderful. In common with all the Symfonie range, they combine durability and warm feel; they're also very easy to change, and until you do change them they stay in place perfectly - in both cases, thanks to the little key supplied with each pair. The only slight difficulty with them is that they don't go smaller than 3 mm, because the size is limited by the gauge of the screw fixing to the cable, so if you want to do delicate lacework you'll need to buy a fixed circular; but for all other purposes I would thoroughly recommend them.