IIRC, ArrowD is a tweaked version of the PowrKoil 18 cover used on the Danger Zone.  IME ArrowD is cleaner in front, but still strong at the break.

The original Speed Zone used a solid version of ArrowD.  The Blue Vapor had the pearlized version.  The Speed Demon had another tweaked cover, called ArrowDF.

As for the core, the Vapor has a lantern-shaped core similar to the one in the HPH, but the core isn't quite as tall.  Both the Speed Zone and the Blue Vapor rev up fairly quickly, pick up the midlane well, and have moderate to strong arc reactions in back.

Hope this helps.
--------------------
"Dispensing conventional wisdom to a fingertip world."

Horrid in Doubles, torrid in Singles...
...that's The Curse of Dusty.

I can't speak to the others, but this is definitely true:
 

quote:

---

As for the core, the Vapor has a lantern-shaped core similar to the one in the HPH, but the core isn't quite as tall. Both the Speed Zone and the Blue Vapor rev up fairly quickly, pick up the midlane well, and have moderate to strong arc reactions in back.

---

I encountered some fairly burnt lanes today - ladies tournament, everything from 7 to 13 FRIED. Some oil inside, however. Tried my firestorm - it just wouldn't finish. Weak tens all over the place. Pulled out the speed zone - JUST what the doctor ordered. Perfect reaction.
--------------------
-- Whether you believe you can, or you believe you can't - you are right.