6 pounds isn't so bad for a tent. depends on your personal preferences. i didn't want to live in a bivy for more than a day or two. i'd draw the line at the mattress though. a simple ridge rest was good enough.
i drug a similar 3-human tent around nz and oz for 18 months, didn't regret the extra living space. considering my (over)load, it didn't add much percentage-wise to the total.
i wanted something with mesh netting to keep out the skeeters and snakes and tarantulas, some hangie things on the ceiling, enough room for me (6'2") to stretch out without rubbing against the walls and sit up without bumping the ceiling, and plenty of space to spread stuff all my gear during a 3-day downpour.
....with a large foyer for cooking during thunderstorms.