Interesting you've said posture D2D...
I've never run on a treadie, but I am neutral about it - do what works for you I think 
However, I keep seeing people 'tigger bouncing' down the embankment and I cant help but wonder if they are usual treddie runners - not sure how else you would develop such a style naturally. These people dont seem out of breath (i.e. running fast for them) so I cant work why they are bouncing so high?
Any treddie runners got comments about style from road vs treddie?? Its just got me wondering...