I think we might be heading a little off topic so I will try to wrest it back a bit. I don't stress about where I tongue from sometimes its well back towards the roof of my mouth others times it's just off my top lip and varying points in between. This depends on where I am in my range, the type of music I'm playing, the effect I want. I can articulate clearly from each postion. So I suppose what I'm saying is in my case don't stress as long as the sound is right.