For a bit of fun I tested out my new SP4 typecover (on my SP3) versus the old type cover and also tried the same on my desktop PC. I used this site: Typing Speed Test - Online Typing Test Firstly I'm a fairly capable typist - I don't stick wholly to touch typing rules but thanks to typing lessons taken on actual typewriters (yes those things) when I was a teenager I do manage to use the majority of my fingers when typing and can type without looking at the keys. Here's the score from the SP4 type cover incidentally I did this one while sitting on my bed: I made four mistakes Here's the SP3 typecover: I made I think 7 mistakes with that keyboard And here's my Microsoft comfort 5000 on my desktop PC. I made 6 mistakes with the desktop keyboard Ha! I have to say though with the SP3 type cover I started off really quick and I was thinking it was going to beat the SP4 cover, but then my fingers drifted off and I typed several mistakes in a row. Similar thing happened on my Desktop keyboard, a misalignment of fingers messed up a few words. All in all pretty similar scores I think the SP4 type cover enabled better finger placement (even over the desktop keyboard??) and less likelihood of drifting off piste. What's your score?