Volume is much better for me with the new one.
On my PC, with youtube and computer sounds at max, I couldn't hear much of it, and as english isn't my main langage, I didn't understood most of it. With the new volume, it's really better, even if I still need to push the volume up.
On the video itself, I'm not used to tutorials video, it's not a format I'm comfortable with, I'm doing much better with the written informations.
The only "criticism" I may have, is that you may want to zoom more when you show something specific, I'm thinking to the plant evolution in this video, for exemple. I also play from a distance, but a close up may be more comfortable for explaining something, like you did for the bugs. On the small imbedded vids, it's hard to read, and on full screen, at least for me, it's fuzzy.
But all in all, it's a very great job, and I'm sure I can't fathom the effort and time you put in this. And I'm sure it'll help people who are more comfortable with videos than I am. So thank you for doing this.