Hmm while looking for some web links I found some interesting links that I will repost into the U-MG-RL thread too…
Search term used: xna analogue stick input
https://www.bing.com/search?q=xna+analogue+stick+input&form=EDGENT&qs=PF&cvid=bb634b83951d4c08bccf00d1428d5083&pq=xna+analogue+stick+input&cc=GB&setlang=en-GB
https://msdn.microsoft.com/en-us/library/bb203896(v=xnagamestudio.31).aspx
https://msdn.microsoft.com/en-us/library/microsoft.xna.framework.input.gamepad.getstate.aspx
http://xboxforums.create.msdn.com/forums/t/58712.aspx
Hope this helps…