I was curious if they all exhibited a common behaviour at the "cheap and cheerful" Chinese prices.
Think about what that question really means; there will be an unknown and pretty much unknowable number of different manufacturers with different designs of different levels of quality, it is not possible to know if they exhibit any common behaviour. Even if you bought up every one you could find and tested all of them against all the others you could never be sure if you missed one. The question is impossible to give a satisfactory answer to.
Buy some and see if they do the job you want them to do.
Oh, please, when you HAVE bought a sample of every one you can find and tested them all one against all the others, please share your results on here :-)