In Yao: Very mediocre quality of strokes, sometime bad. And sometimes three or four out of ten characters have configuration problems. But the piece as a whole usually looks comfortable enough.
In Li: One can still see control of the brush that can only be obtained by training. The orderliness derived from this brush control is perhaps what makes some of his messing somewhat interesting. That is, if there is any thing agreeable in his pieces, it is still the traditional old stuff at work.
I think Li is just being harmlessly playful (just like my poems dedicated to his pieces). But when his fans take it too seriously, he should remind them not to. Yet he doesn't seem willing to do that.