I just gave my YAPC::Europe presentation to Stella, to see how long it would take. Since she doesn't really speak English, she couldn't critique my presentation skills, but I could see how long it would take, approximately.
I spent about 10 minutes on the 23 slides. Since the talk is scheduled to be 20 minutes long, this means that I can talk more slowly, include a bit more explanation, and/or have time for questions.
I was really nervous and tended to keep to the text on the slides. I noticed in a couple of points when I wanted to add some more text that I was unsure of what to say or how to phrase it, so I'm glad for the text I already have on the slides.
I also noticed that one slide had a couple of wrong words which messed up the sense, and that one image was missing from the ZIP file and the web site where I had stored the presentation. I corrected that and re-uploaded.
Urk. I hope everything will go well.