I have always had the Cheyenne but very curious about why or why not the pencil roll?  I see more and more pencil roll seats these days just wondered about why? 

I always had the cheyenne roll until my current saddle, which is a Seven. I absolutely love it. The pencil roll cups your butt and gives you a little more room. 

You see more and more high waisted jeans and crop tops. Doesn't mean it's a good thing. 

My issue with a pencil roll is that it's difficult to tack up for me.  I'm 5'2 and my horses are both 16 hands.  It's much harder to grip/swing the saddle up with a pencil roll than a Cheyenne roll.  Just something else to consider.