Aaron: "How would you rate the space on the CR2 for two 6' + people? What about these same people plus gear? What about 2 people plus a dog, and 2 people plus a dog and gear? Just wondering how it would perform in all these scenarios at under 30 square feet."
I believe MSR claims a floor area of 29 square feet (50" x 84"). In the BPL review Will measures the width of the tent at 40" and then uses that times the length (84") to come up with a figure of 23.3 square feet. I believe the actual floor area is between these two numbers because the tent does get somewhat wider towards the corners (think hourglass shape). Will measures the width at 46.5" near the corners so the average width as measured by will is more like 43" which correspond to around 25 square feet I'm guessing. Measuring the CR2 is a bit of a grey area because the edges of the floor do not have a clear edge and the walls lift up the floor so depending on how loaded the tent is, the width varys. I do feel that 42" is a fair number for the width of my tent at the narrowest point (the middle) so considering it's 46.5" at the corners my tent probably averages about 44" wide. By loading down the tent near the walls I can achieve a 46" wide floor in the center but this is unrealistic because I'm purposely pushing the floor down which isn't something you do while sleeping. Anyways, my point is that the actual square footage is likely in the 25-26 square feet range.
To answer your questions, for people around 6' I feel that the length of the tent is not an issue. I am 6' right on and the tent seems plenty long when I sleep in it. David has said he fits at 6'1" but his friend doesn't at 6'4". Using a 72" sleeping pad as a reference, as long as you (in your bag) aren't 8" or so longer than this you should fit. That leaves 4" to allow for the slope of the walls.
With two adults in the tent, you will be taking up the entire width of the tent when you sleep. I don't find it uncomfortably crowded (I would share this tent with someone who is not my wife), but there certainly isn't room to toss a pack beside you.
The only extra floor area that you might have is 6-10" at the head (or foot) of the tent because the floor is about 7 feet long and a 6 foot person in a sleeping bag probably measures about 6'6". You could possibly put your packs at your head (or feet) but the would definately be contacting both the tent wall and your sleeping bag. My dog normally sleeps at my feet in this tent but she is small (19lbs) and just fits. I generally do not keep large gear in the tent with me and this gives the tent a spacious feel in the length regard.
For the gear, I normally bring my pack with me into the tent while I get ready for bed. Then when I'm ready to sleep I put both packs outside in the main vestibule along with our shoes that are already there. A medium sized pack will not fit through the vertical zipper into the far vestibule. You could pass your shoes through to this vestibule but then you're passing dirty footwear through your tent. If I have a lot of gear I actually put it in the far vestibule by removing the stake holding the vestibule down, tossing the gear in and then re-staking the fly.
If you brought a large dog in this tent with you, it would probably end up sharing some square footage with you. It could probably sleep between the two of you down at your legs but it would be on your sleeping pads. 2 full size (72" x 20") pads take up pretty much all the width of the tent and only leave a foot or so of space at either the head or feet.
Really what you need to know is that the tent width isn't generous so your sleeping bag will probably be brushing the sleeping bag next to you. You won't feel like you're spooning though. I don't think it's uncomfortable but people who really like their personal space might find it tight.
Also, I wouldn't plan on keeping much large gear in the tent with you. If you are okay with the width and don't mind using your vestibules for the packs then you should be fine. Honestly, if you have a 70lbs dog then it's probably going to be a bit tight in there. The dog will probably wind up partially laying on one of you.
Okay this is getting long....I think I've covered the question :)