You mention more space......but from my experience in trying tarp type shelters, I lose a lot of useable space because of the slope of the tarp walls. For instance, as an example I'll use the new SO BT-2 which is listed at 96"x108" (not rectangular however). That sounds like an incredible amount of space. However, because of the slope of the walls I lose about 18" on each side as far as useable sleeping space, without having my feet or head touching the walls. So that "large" space is suddenly now about 60"x72" of useable space (other than storing some items in the low clearance wall slope). For someone that's 6' tall, that's not an issue.
But when a particular shelter appears to look great on paper, at 6'6" I suddenly can't fit well in that shelter in real life. Some tents have the same issues as well, depending on the slope of the walls. That's why it's so tough to buy these things sight unseen, just going off of listed specs. I can't even begin to say how much gear I've gone through over the years because it looked great in principle, but in real world it failed miserably for me.