I know that size/height effects running speed. But does it effect his ability sneak? A smaller character model should have a better time sneaking in the dark than his larger counterpart. 
 
For example, does a Bosmer have a better time sneaking around than Argonian because he is smaller and thus making it harder for light sources to shine on him?


  I don't know about taller characters, but for the .4 height ones their "hit box" remains the same size as their race's normal height. Maybe that applies to your tall guy's detect size, also.