If I use my laptop at the local library (Marrickville Library in Sydney Australia) I get a message saying this site has been blocked due to inappropriate content :)
Some people are better off without float as they don't put their feet in the correct spot if they use float.
In regards to Speedplay vs Look, I doubt that there would be any difference in power transfer.
There is a lot of driver hostility in Sydney, but its not just directed at cyclists, its directed at everyone.
Truth is that 99% of drivers are careful and considerate, but 1% is a hell of a lot of **** heads.
I use zero float cleats. With zero float cleats, they need to be setup exactly right, if you do not have the skills to set them up exactly right, then you are safer with the 10% float ones, as this caters for setup error.
There are some good answers to this question and the Data that 531Aussie has provided is useful for the explanation.
A common statement is that at 40kph, 80% of the effort goes into pushing air out of the way. The bulk of this air is on the body and the largest part of the body is the torso...