I agree with Mike that it's nice to be able to print out the lessons. For the newer lessons, I write out the tabs in pencil on tab paper for a handy reference. Which raises a touchy question: the swing lessons have tab that gives time indications--such as coming in on the 'and' of one or whether a group of notes is a triplet or a sixteenth and two eighths and so on: could the tab for Newer lessons give time indications, if only it is the grouping of notes with a bar???? It would sure help me, and I suspect others too.
On another front, as the number of lessons increases, might Duke add an indication of which lessons are aimed at beginners (-in a genre, such as swing) and which are more advanced? Maybe just a "Beginner's Corner" with a list of lessons that cover the basics and a 'suggested' path through the material?
Finally, and this may be just because I'm getting older, but when the lessons are listed down the right hand side of the page, I find that text too faint. (If the laptop is in my lap, no problem, but if the laptop is on the desk and I'm in my guitar chair, well, I find myself wishing the font were darker so the titles would be easier to read.
Having a blast with the lessons! Glad I found this place and I plan to stick around.
Mark