I have not tried the Rain-X blades. I'd recommend one of the "structureless" blade models. I currently have a set of Bosch Icons on my car. The Bosch ones are on the pricey side, but they work very well. This newer design contacts the glass with the same contact pressure from one end of the blade to the other, without the development of "pressure point streaks" you sometimes get from older style blades that have a "skeleton" pushing down on them. this is a small picture, but should help visualize this if you haven't seen them before:
EDIT: Whoops, sorry, we're having technical difficulties. For now, just google "Bosch Icon blades" and you'll be able to see them in a couple seconds.