It's not a four season tent, but definitely good for 3 if you get the door and cuben bathtub floor. I think it'd be at around a pound.
It'd be a lot cheaper with a Tyvek groundsheet and use duct tape to make a bathtub floor. It works quite well actually. But if I had a wife, I'd spring for the cuben floor.
I have a solo, and if you're smaller you could even fit two in it (it would be tight), I'd imagine the duo would be that much bigger. It's probably as close to a tarp as I'll ever get. It would make a stellar solo tent.
It's not freestanding and takes a bit of real estate because of the guylines, but the packability and lightweight is very very enticing. I just got a Double Rainbow (using it this weekend) and looking at it compared to the Hexamid solo, it's quite something…. I now realize how really small the solo is when packed.
I find the solo very comfortable. Great views, airy, excellent ventilation. I had a night of heavy rain (not blowing rain though), didn't have a door and was completely dry. No condensation. I"m not sure how it'd do with two people but I'd imagine it would be fine, lots of mesh. Speaking of mesh, the mesh floor is very durable. I was concerned about it before actually using it, but once I did, it has proven to be no problem at all.