I've used this tent for 30+ nights now. The vestibule tension is actually fairly easy to adjust by changing the angle of the front ridge guyline via its lineloc. That, and by making slight adjustments to the position of the front corner stakes. I think the vestibule is pretty well done, as far as trekking pole-supported single-wall tents go.
As for achieving good tension on the rear panels, this can sometimes take a bit of practice, though I've yet to find it necessary to use the stabilizer pullouts at mid-panel, left and right. Will's photo of this part of the tent seems to indicate a somewhat high angle to the rear trekking pole. I find it useful to insure that the pole is pulled out via the bottom boot as far as possible, deepening the pole angle, both to tension the lower perimeter of the rear panels and to achieve a nice, taut bathtub floor.
The rear vent awning isn't especially taut, perhaps by design. I eliminated the loop in the rear guyline to which the bottom of the awning is tied, and instead tied the two directly together. This is fiddly to do, in terms of getting the right angle for the awning, and I don't recommend it, though it does reduce flapping in high wind somewhat.
One issue that might be addressed is the use of this particular type of #3 zip/slider combo for the large doorway track, which seems to have a fairly short service life, especially once grit accumulates in the system. It helps to close the door via both zippers, meeting in the middle, though I've yet to make it more than a couple of months' accumulated use without a zipper failure. (The sliders can be replaced fairly easily, but a worn zipper track will tend to wear out new sliders faster than the originals.)
A really nice design, by and large. Anyone else seize the opportunity to install a clothesline along the interior ridge?