Great info video Michael! Like some other viewers here, I also experienced lag on this video compared to some other dtube videos. I really do feel like I'm thrown back in the days when youtube was in its infancy. I wonder if would help if you compress down the video quality/bitrate. Dtube does not have options to scale down the video quality according to the user's bandwidth like youtube does. But since your videos have a lot of static slides, you can get away with a lot of video compression without reducing the apparent quality, depending on the encoder.