your shelter should never weigh more than 5 pounds if youre traveling on foot.
The THREE MAN version of the REI quarter dome tent is under 5 pounds! I have the 3 man, which I carry and my fiance and I share. I've also used the one person version of the quarter dome, which weighs in under 3 pounds.
These things won backpacker magazine's editor's choice award for good reason - a heck of a lot of tent for the weight, and a dang good value too.
The ultra high end tents are certainly nicer than the REI quarter domes, but for the price they are amazing.