The delay of the comparator seems to be varying around a little bit less than half a tick. This is not consistent.

See the graph for more details, the low shelf was always as long as the high shelf.

I also uploaded a pic showing my test setup. Basically I created a comparator clock and added more comparators one by one. Please note that the repeater line is not showing correct values, because I didn't pause the game to make the screenshot. When testing this, I only read values after pausing the game.