Hi Zeno-
I have no experience with the Moonbow 40/20 tent but I can offer a couple of insights when comparing it to a Tarptent Virga 2 or a Six Moon Designs Europa 05. First, a catenary or arched roofline makes a huge difference in wind stability because it is so much easier to achieve a taut ridgeline. The Tarptent and Six Moon Designs tents both have catenary ridgelines which is a notable difference. Check out this article to learn more: http://www.backpackinglight.com/cgi-bin/backpackinglight/00149.html
Also note the bathtub floors of these other designs, the hooped rear ends (which increases usable space), and the increased vestibule area. These are some pretty great designs- look forward to upcoming reviews of both of these new designs.
Not to discount the Moonbow though- that’s a great company and their design is both simple and lightweight.
Enjoy your research!
Doug Johnson
Shelter Systems Editor