Hi FrankB.
Firstly, thanks so much to you and those who are working with you, for endeavoring to make top quality tutorials, they are greatly needed as you know!
I watched the tut with safari (current version), as I use safari for most web surfing.
The video quality was very high, I had no problems viewing and could see everything perfectly! Much better than almost everything on youtube.
The audio was clear and crisp. no problems.
Your english is very good, and understandable. And your accent adds character to the product.
As to html5, I say go for it. If guys like you don't produce content for the format, we will never get rid of flash. On the other hand, I understand that the tuts need to be available to all.
Keep it up!