I was sold on this until I saw the pic of the inner, and realised that the door zip is inverted. Ie, the zip runs up the centre then across the top, leaving the netting connected at the bottom. I’ve had and used tents over the years that did that with the inner net, and, I’m not a fan. Mosquitos have more opportunity to come in (my number one concern), and I never liked how the door would then flop down, sometimes into the mud/water in the vestible (not impossible to solve, you just have to pay more attention to it). It would also weigh more, as, the A+C sides are longer than the A+B sides of a right-angled triangle…ie more zipper length.
I really prefer the idea of two seperate, straight zippers on the A and B sides (not a single curved zipper), because, at least theoretically:
– if one zipper breaks, the other is still working fully. The door is mostly closed, at least, either way. If the vertical A zipper was the one to break in its entirety, I could temporarly lightly handsew the top ~1/3 to 1/2 to reduce bug ingress where its most likely (at the top), while still being able to wriggle into the inner from the bottom.
-theoretically the most common failure point for a zipper will be where its used the most along its length, ie the end that you start to open it from. In the A+C scenario, this is indeed at the top. Again where most bugs come in. With the A+B scenario, that is from the bottom where its less an issue, and the zip might still be useable for the upper sections.
– straight zippers last longer than curved zippers. Shorter zippers, theoretically, have fewer failure points (individual teeth) than long ones.
-with the top opening A+C zippers, you have to unzip them all the way down to their bottom, otherwise you risk putting more strain on them (the remaining engaged teeth) when you enter or exit the inner tent, as you put pressure across the fabric (I noticed this problem years ago in a Macpac Olympus).
-straight zippers are easier to sew in… useful for eventual replacement or repair anywhere in the world by someone far less skilled and experienced than say, Ron. I can also more likely find a shorter length of zipper (in any size) to fit rather than a longer zipper to fit either an A+B curver, or a C length.
– I can unzip the A, or B zippers individually, and partially, in order to reach through to the vestible to grab things, adjust the centre pole, etc, without opening up much mesh. Especially I’m not opening mesh from the top, which is where more bugs and Mosquitos hang out, and I can’t partially open, easily, from the top to reach something on the floor of the vestible.