This is an interesting thread!

Also re the state of mind, I agree totally. The way I look at it is once you have the dexterity to alt pick accurately at speed with the right hand and can fret accurate legato with the left hand linking the two together is NOT just a matter of practice.
If you think about it without a guitar in your hand and visualize being able to play it and imagine exactly how to do it then 'the penny will drop' and you will be able to play it. It has been proven that creative visualization improves performance.
I watched an interesting program about how visualizing a physical movement over and over in depth actually created something like a neural pathway for the action so that when you go to execute it your brain is not trying to get your body to do something new that it doesn't entirely understand. They illustrated this by having a psychologist mentally preparing gymnasts for new movements they could not perform - needless to say after going through the process they improved vastly.
Seeing I get so little time to play at all I have to rely on this method all of the time because I don't have any time to practice. Since I started consciously doing this about two years ago my playing has gone to a level I would never have imagined being able to do before. It sounds a bit 'alternative' but its grounded in science, try it!