that was the general consensus with the monowiper - that it does not clear the windshield quickly enough in hard rain, even on the high setting. The reason is that it has to complete a wider arc per sweep, compared with one of the wipers in a two-wiper system. And in a 2-wiper system, two portions of the windshield are always "freshly swept" at any given time, compared with the monowiper. Another way of looking at it is that a 2-wiper system has more linear feet of wiper squeegee material.

another reason is that the monowiper inherently has more friction in its actuation mechanism, that makes it extend into the edges of the windshield - running it at a higher frequency would unduly stress this mechanism (as you can imagine from the sounds it makes as it sweeps the windshield).

like others in this thread, I just use RainX washer fluid. On the highway, I mostly need the intermittent or low settings since most of the rain beads away to the sides.

i like the monowiper though - it just looks so cool, viewed from the outside, when it is in action. It looks like a male fiddler crab with its oversized claw ...