We sell a wide range of kits here in our KnittingHelp shop. I compare the cables of the kits whenever there is a new set on the market, because I'm always interested to see how sets will work for Magic Loop knitters, and I often pull them out to evaluate them side by side, bending the cables to see which bend the most easily. I'm doing it again as you bring up this question.
Squeezing a cable to get it out from between the two stitches is always going to be a bit annoying, because all cables will all have a degree of resistance to this, which is a good thing in terms of holding the knitting in a good position relative to the needle shaft. So the cable needs to be pinched to the point of kinking it a bit, to get it to pull out from the knitting. This is unavoidable in the kits I've seen.
Here's what I know about cable flexibility....
Stiffer than your clear ChiaoGoo cables would be the red cables in some other ChaoGoo sets, the extremely stiff Boye Needlemaster cables (we don't sell this kit, although even this one has its strengths), and the (not stiff, really, but overly thick for ML) Denise cables. And actually even the new, bright colored Knitter's Pride Cables are a bit stiffer than your clear ChiaoGoo cables, although I'd be surprised if even these were written off by ML knitters, because they seem to me within the range of reasonable flexibility for ML.
Less stiff (so most appealing for ML) would be: the old Knitter's Pride black cables (which we still sell, by the way, and can be used with any of their kits). I'd expect these to be the most popular among ML knitters. Some of the HiyaHiya cables are less stiff, particularly the sock set cable, and the standard small set. (Note: Their Large set, which has bulky needles, has a thicker cable. Same blue color as the small set's cable, but noticeably stiffer.) Hiya Hiya does sell a bamboo kit, which we have just started to carry--I don't think it's even listed yet! Give @sheldon a nudge if you are interested in something you don't see in our store yet. Hiya Hiya's manufacturing quality is quite high, as is the ChiaoGoo. The Knitter's Pride sets are well loved, but are undeniably fiddly in their cable threading quality. We replace cables for free when they fail, if people buy through us.
I'm not a Magic Loop knitter myself--I do know the technique, and even teach it, but I personally only use it occasionally, when I don't have my DPNs handy! If you have further opinions about the matter, I'm completely open and interested to hearing them. If you have further questions, I'm open as well!