Jimbo
I also like space above me for ventilation and being able to see out. That is why I prefer my tarp to the one that comes with the Hennessy.  I think I would prefer the top entry because of the ease of getting  the sleeping bag on top of pad and right side up with me in it. I would also like those under pockets for warmth.  The things I like about the Hennessey over the Clark is the flatter bed and being able to sleep on my side.  Actually I usually sleep half on my side.  In a hard bed I sleep either all the way up on my side or not on my side.  In my Hennessy I usually sleep with my shoulders at about 45° to the ground.
MagicPaddler