I think the screeching has as much, or even more, to do with the condition of the windshield than the condition of the wipers themselves. Windshields get pitted quickly, and over time zillions of mostly microscopic pits and scratches in the glass show up - and I believe that those pits and scratches cuz the screeching. Rain-x actually helps fill in those pits and scratches, and it really does help vision in the rain.