Yeah, my first ever filers were Chinese ones and also a set of color once to start playing with. You know, in the beginning many photographers are just mad about colors in landscapes and getting some crazy ones. Then for quite a long time I jsut stayed with my LEEs, which is yes, still may have a bit of color cast, but very good especially with Canon initial color palette (well, at least completely fit my taste).
And now, since I was searching for not expensive way to still use some ND + Grad on 12mm Sigma, I just stumbled on ebay on those cheap Haida set (I guess they were manufactured for Cocin system). And damn the combination of 8ND Haida + ND Grad of Lee jsut gave those insane colors combination and mixture. So far I'm just in love with it, will see for how long ;) There is almost no any play with WB here, thats what I'm getting straight from the camera, just some additional color grading of course