I like the statistics of the different writings he writes at the end, however I would have liked a comparision of the different layouts while writing different programming languages (C, Ruby, JavaScript, etc).

I've seen two problems with alternative keyboard layouts: a) they are not done for programming (keys ~|!<>_-/"' are oddly laid out) or they are not made for international languages (Spanish in my case, for which ñ,á,é,í,ó,ú are difficult to find. Or worse yet (in case of Dvorak) when using an "international" version, the programming-related keys are horribly placed.