I just recently removed, cleaned and replaced my wiper set up, with little improvement as far as speed. Yes they operate better but the difference between slow and high speed needs to be evaluated by counting and stop watch.
Some one here also posted the # of RPM's the wiper motor should be working at, but couldn't find it.
By the way, I agree with "Rain-X" for the EXTERIOR of your windows, it really REALLY makes a difference on how much and continuously you have to use the wipers.
HOWEVER, and this is important, DO NOT USE THE ANTI-FOG RAIN-X on the inside of your windows. This stuff will ACTUALLY FOG your windows PERMANENTLY. There is no fix, you will regret it for the rest of the time you own the car. Simply put, throw this stuff away.
I put some on my Acura and after half a dozen attempts at removing the stuff (since the 3 attempts at "polishing" per the instructions" did NOTHING, didn't get clearer, just stayed the same) using Windex, Automotive Glass Cleaner, Alcohol, Mineral Spirits, and lastly Acrylic Thinner finally was HAPPY that I got a rock chip requiring the windshield be replaced. I still have the crud on the side and rear window, now just wondering if I can get one of the neighbor kids with a BB gun........