OK, I've been away, camping in my Haven, so only just now glanced at this thread.
I think I must be using a different Haven than what people are discussing here. We are talking about the new SMD Haven, correct?
Grip-clips?
The Haven does not need grip clips, the tie-outs are already available and I have had to use them with great success in strong wind.
Sagging walls?
It is summer, but we have experienced some temperature extremes and at least 6 rain showers. I have not had any sagging walls, the inner net has not touched the outer once.
It sounds like some people need to spend some time learning how to pitch it before they write a review.
Headroom issues?
The Haven has more headroom than any other two person double wall shelter I've ever used. A previous 3 person, 6 lb, dome that we considered spacious doesn't have as much headroom.
Don't believe otherwise, for it's small footprint, it is huge.
Ventilation issues?
The Haven has more ventilation than any other two person tent we've ever used. Of course if you close it down tight it could be stuffy, but why would you?
You pitch the fly first, so no wet inner if you have to pitch in the rain.
You can open the vestibules wide open, even if you suspect it will rain. When it starts raining reach out and pull down and zip the fly up. Exiting the tent is not required.
I will admit there is a price to be paid for the headroom and small footprint. That price is steep side walls.
Steep side walls, like tunnel tents can flap in a side wind, but this has proven to be a non-issues when I use the extra ties.
I was only able to skim the posts, so sorry if I missed some of the comments.
I think I'll take the PUP TENT from now on when I backpack with my wife.
I have owned and camped in many shelters in my life, including pup tents, flat tarps, bivys, freestanding domes, tunnels, a-frames, tipis, pyramids, …
I consider the Haven to be the best designed double wall, bathtub floor, ultralight two person backpacking shelter made so far. It might take some experience and practice to understand why. For me it was a no-brainer after only a few nights with it.