I just received the MSR Hubba Hubba HP (2 person), European Model. I had read quite a few posts here and there claiming that MSR tents are not UL, but now that I've received one, weighed it, and set it up in the living room, I have to say that I'm very impressed. For a double-walled, solid fabric shelter, it is very light indeed. The fly sheet and inner materials are amazingly thin and light. Every detail has been carefully thought out, including all guylines, straps, guyline buckles, zipper pulls, and cordlocks, all of which are the lightest available. The entire package, including everything, weights 1724 g. That's 648 g for the fly, 598 g for the inner (which is solid), and 478 g for the entire pole set. The interior height is 100 cm. The interior floor area is 2.8 sq. m. and both vestibules together are 1.6 sq. m. Floor length is 2.1 cm and floor width is 1.3 cm. Being "freestanding" makes it versatile when doing things like bicycle camping, when often you end up on tarmacs and roadside campgrounds where stakes are impossible to get into the ground.
The Hubba Hubba compares very well to the TarpTent Scarp (also a double wall shelter), which, with the optional poles comes to 2012 g. The Scarp has an interior head space of 114 cm, interior floor area of 2.9 sq. m and both vestibules together at 1.16 sq. m. Floor length is 218 cm and floor width is 132 cm.
The 100 cm head space doesn't feel at all confining or too low. In fact, because of the triangular end poles and the overhead transverse pole the entire interior of the Hubba Hubba is usable. I had no trouble imaging four people comfortably sitting inside playing cards.
I love the subtle and cheery green color of the fly. It looks at once natural, but at the same time bright enough to make rainy days holed up inside bearable.
Not sure I like the stakes all that much. They would be painful to try to push into the ground with the palm of your hand.
I moved away from inner-first shelters back when traveling in Europe in 1995, when I bought and used a tunnel tent. But my partner really likes this tent and I think I am going to enjoy using it for two.
I still have to use it outside, in the mountains, but for now I can really recommend this tent if you're looking for a 2-person, double-walled, double-vestibuled, solid-inner tent.