I'm considering a BA Copper Spur UL1 after seeing it on a trip recently.

How high is the peak of the CS fly door? Anyone know if it lower than the Tarptent Moment?

I'm having difficulty picturing the wall slope at the head end. It seems there are no straight-on photos of the wall which shows how much it slopes inward. Even better would be a photo with a person or sleeping bag inside the tent and showing the wall slope at the end.

Here's an insightful review with great photos:
http://www.petesy.co.uk/big-agnes-copper-spur-ul1-review/

One photo shows the minimal side wall slope very well.

The guyout points seem to be not well thought-out. It apparently has 3 at the head end, which is the end containing the vent. It only has one at the bottom of the fly on the foot end. It seems like you'd want to pitch the non-vented foot end into the wind, but that end has less guylines. The tent structure seems to rely on the flex of the poles with the hub to withstand wind gusts, but apparently the poles still get bent sometimes. Guyouts seem like a better strategy. I wouldn't mind sewing on my own guyout points, but I'm sure that would void the BA warranty. Not a big deal, as I'll be in the forest 95% of the time anyway. It apparently holds up acceptably for even the open, windy, rainy UK.