The inside is coffin shaped like you can see by the outline of the foot print. At it's widest point my wife and I can lay down side by side flat on our backs without touching each other or the wall. The foot of the tent is also plenty wide and tall for feet.

As I mentioned before it's tall enough to sit up in between the beams even at the low side. Almost tall enough to kneel in...doing things inside the tent like changing clothes shouldn't be too hard.

It's not going to hold a ton of gear once we're in. Time will tell on that one, but even if packs have to sit outside, I'm fine with that. The vestibule is adjustable at the cost of tent space which is a feature I like. I can make the 'bule just big enough for boots and still have enough room inside for at least one pack.