I recently got a set of Chiagoo interchangeable bamboos and I love them!! The cord rotates when you knit and is very pliable and the tips are nice and pointy. The needles themselves develop a nice patina as you use them and are just slippery enough to move knitting along. I highly recommend them.
I have the cheap ones too. My problem with them is the yarn sticks and I constantly have to push the stitches forward. I broke down and got the Harmony and love them. I use the cheapies as a back-up