Jeremy, Todd: I'm 6'5" and I had the impression from reviews on this site that the D-Rainbow was a little tight –lengthwise– for the normal-sized backpackers like we three. I mean, I noted the Oompa Loompas are nearly unanimous in praise for this tent, but I honestly had it in my head that it's a tad short for us.
It is two inches shorter along the floor than the (heavier, slower pitch) BA Copper Spur UL2 I'm using. You regular fellas are fitting fine without dragging the toe of your bag into the ends of the tent, etc? That fast-pitch video on the Tarptent site is very compelling.