David: It was not particularly difficult to sew. Mostly straight seams, although some were pretty long. The catenary curve was no problem since it's mostly straight at the level of a foot or so. I just pinned all the seams and it worked fine.
Jerry: Yes, about 12 feet of ridge line, half is 6 feet, so about 6 inches catenary at 1"/foot. I didn't use a template, instead I marked one piece and lined another below it and held them together with clips while I cut. It worked fine on three of the big triangular pieces. On the door piece the zipper and flap in the center caused some problem so when I was done, much to my chagrin there was an extra inch of fabric cut off compared to the other panels. All my fault for taking short cuts due to time pressure. Could have been avoided if I was more careful or if I used a template for each cut, rather than cutting two edges at once.
Jerry and Andrew: I think the vent is too small, although it was quite humid each night and it rained a few times, so it is possible even a larger vent would not have stopped condensation. The condensation actually wasn't that bad, no drops raining down, but the walls were fairly moist in the morning, and you got wet if you rubbed against them.
Ultra Magnus: Sewing such a tent does not require great skill. If you can sew a straight stitch and a flat-felled seam, and a little zig-zag for reinforcement points, you can do it. Cutting is tedious but straightforward. Design is a different matter, you really have to think through everything carefully (and be comfortable with simple geometrical calculations). On a small project you can mess up a piece and just rip out a seam or two and make a new one. On such a large project the pieces cost too much. All the better if you can get a design from someone else.
I did manage to catch a fold or two and had to rip out some stitches and sew again, then seam-seal the holes in the fold that got caught.
All the cutting, sewing and finishing maybe took 20 hours, I didn't keep track. Not that long if you spread it out. Having someone to help with the cutting can save a bunch of time (I had some help, not much). Having a large space to lay out, measure, cut and sew would have helped (I did it all in a not terribly large dining room and living room).