Has the voice been improved overnight, or am I just understanding it better?
It seems to be a bit clearer, not sure whether that's just practice or whether there's been some tinkering?!
Yes, personally I just complete one lesson. I just got done with genitives and won't go to the next lesson (pos. pron.) until tomorrow. I picked this up from pimsleur...learn a bit of the language, stop and let it all sink into your brain and let your brain organize it while you sleep, then do another lesson tomorrow. Tomorrow I will do genitive again to jump start my brain, then after that I'll continue on to pos. pron.. Then repeat the process with pos. pron. Usually this method helps as I still remember how everything works in the previous lessons, like it's basic instinct.
That is what I'm doing as well, only I strengthen the three latest skills I've finished before moving on to the next one. That way it might take a lot longer to finish the tree, but I think I learn a lot more from this course than by rushing through all the skills in a short amount of time.
I have taken Spanish in my university (currently taking a class also, plus am on level 9 on Duolingo) and I still have to listen to EVERY Spanish sentence slowed down on Duolingo, often repeating it. BUT, with the Danish, I seldom have to slow it down (I do repeat it a few times, especially if it is a long sentence though).
I noticed it too! I can't tell if it's been improved or I just understand it.