Otter -

Some tarptents are available floorless, but the Rainbow and Double Rainbow have a bathtub floor and mesh walls suspended from the single-wall tarp; they're really tents.

I'm recommending your taking a look at these based on your need to use them in summer, the amount of room they give you and the airiness, plus the flexibility of the vestibules. You'll get a lot more ventilation in this than in the Dragontail, and a lot more ways to open one or both vestibules to create views or ventilation. The Dragontail (and other similar single-wall tents would be sweatboxes in summer.