I would say the SJMY is the nicest, then the Tobeco and lastly the SXK.
But I only have one of each, with Chinese quality control you'd probably need a few of each to make a fair comparison.
My SJMY came issue-free and has been nothing but perfect, my Tobeco needed to be taken apart and re-assembled before it would wick properly but functions nicely now, although the threads aren't as smooth as on the SJMY.
I haven't really figured out how to stop my SXK mini from leaking. I haven't tried very hard neither though, I just retired it and ordered another SJMY instead.
Others may have different experiences.