I do not think that the argument from illusion is successful because it does not manage to convince me that there is a gap between appearance and reality.
In order to to establish a gap the argument would have to show that some things appear not as they should. We have already established that, using our cognitive faculties (including experience and reason), the stick should "appear" bent when under water and it does appear bent under water. In one important sense however, the stick does not appear bent - it appears how a straight stick should appear when under water, so in that important sense it appears straight.
I think the example of a tree seen in the distance is easier to grasp. The tree only appears small in one sense. It actually appears to be a tall tree seen at a distance, which is exactly what it is, a tall tree seen from a distance.
So, to pick up a challenge I issued earlier, does anyone have an example of any perception that does not match reality, once we have factored in human reasoning and experience? I am discounting hallucinations and optical / auditory illusions because we know that we can on occasions be deceived.