Paul, the height is as stated by MSR.
Steve, I plan to be using the Hogback this summer with the kids but at first glance I would say the Hogback has more room, certainly more area.
No we never got to use it in any rain to speak of, sorry. I have reviews of rain gear that have barely seen any rain on hold. I can't control that Peter, you may need to talk to the Big Guy... ;-)