Taking notes collaboratively with the help of the internet was interesting. Though, not very efficient as I think.
At the beginning I had some technical problems with my network connection. So I couldn't take part in the collaborative note taking for the first 20 minutes or so. When I got my connection working again I had problems to get into the topic again.
Assuming no technical problems during a session of collaborative note taking, this might work very well. You leverage the knowledge or ideas of the other participants. This way you might learn more about a topic or at least don't oversee some important points.
However, I think it is quite difficult to pay attention to a presentation and take notes on the computer. Or even reading what other people are writing and thinking. This can be very distracting from the actual presentation and maybe lead to getting completely lost from the topic.
When taking notes "traditionally" with pen and paper you can more easily look up to the speaker, without having a screen in your sight. Although I consider myself as being quite fast with writing on a keyboard, I'm still faster taking notes with a pen. Additionally, on paper you can easily make some scribbles or annotations to previous notes. Trying to make a scribble on the computer (assuming the "collaborative note pad" allows to so) is a pain.