Some people asked us, which wing we prefer and now I will try to answer that question (not easy).
First of all, both wings are really good and comparable, but there are some differences.
Price: No.1 ~100€ and Zeph II ~140€. Both kits include parts like cfk/gfk rods, foil, motor mount etc.
I would recommend to reinforce the LiPo bay on the ZII and to use a stronger Cambox, so you might pay another ~60$ for TBS Zeph II accessories.
Material: No.1 is made out of EPP, the Zeph II is made out of molded EPOR. If you crash, the EPP is easer to repair, so i prefer EPP for a wing, but the EPOR is ok.
Build process: The Zeph II is easier and faster to build, if you use the suggested cut outs, but you need specific setups to get the CG right (for example the TBS or Ritewing 4S Setup with 2x 3300mAh 4S LiPos etc.)
I used comparable 3S Setups and 2x 3000mAh LiPos in both wings.
Flying characteristics: The ZII is more agile but you can easily oversteer it so it can stall critically. The No.1 is still controllable with full elevator up and slow speed, so especially for beginners i would not recommend the ZII. If you are familiar with flying wings and you got good flying skills, the ZII is no problem. The ZII tends to shake around its yaw axis, but i found out, that this is not a big deal. If you have built it correct, because it only shakes around the yaw axis, when you control it pretty rough or when there are some strong gusts.
The No.1 can fly slower (my ZII does not fly really good when i slow it down under 50km/h), but it flies pretty nice and efficient at 65-75km/h. Top Speed is comparable with similar setups (in my case both wings do ~110km/h straight forward with no wind).
If you have built your No.1 wing really good and clean, it will definitely glide better than the ZII and it will also handle slow speeds better, but if you have not much experience in building flying wings, it can reduce the flying performance of your No.1 wing, while the Zeph II is so easy to build, that you should achieve to get a good wing, without having much experience in building those wings.
Size: The Zeph II is pretty compact (~1.4m wingspan) which is nice, but it also got a big wing area, because this wing is deeper. The No.1 got ~1.56cm wingspan.
Conclusion: If you like to build planes (and if you are good at it), your No.1 wing will perform slightly better, than the Zephyr II, but if not, the ZII might be the winner. I like the compact size of the ZII and the clean concept, that makes it easy to get a nice flying wing. On my No.1 i prefer the better slow flying characteristics and the fact, that it’s almost impossible to stall it critically.
So overall it depends on your building skills and flying preferences. I will stick to my ZII, Leo will stick to his No.1 and we are both fine.