I must say I love the idea of this kite and it looks awesome and great website etc so I love the idea, but agree RE the concerns on durability so I did a little digging (disclaimer I have recently started selling Gin/Flymaax but will be as objective as possible as I love these types of kites so am interested). Anyway I know some things about foil kite materials and why they are chosen and the trade-offs of going lighter as this is a big deal in race kites. Also over the last few years there have been some big developments in rip-stop material construction that lots of people don't know about. The Soul is a great example of how things have changed, the original Soul material was ahead of its time and was super light and non-porous to levels not seen before, however there were issues with that generation of material. Generally when this material is made as thin (and light) as possible you have to do that by either having less yarn and/or less coating. So they went as thin/light as they could with the technology available and I think ended up around 32 grams (per square meter)/gsm. Around this time most race kites were pushing similar technologies down to around 27/28 gsm and they were amazing but this was done by reducing the coating that is baked into/onto the textile when it is made. This means that as the kite is rinsed (swum) the kite coating disappears and you are left with a porous kite which can cause all types of issues. So durable kites were heavier and you could buy lighter less durable versions.
So what has changed? More recenlty the paraglider and kite companies have worked with the textile companies (there are two that provide for most of the para/kite industry - Porcher of France and Dominico of Korea) and they came up with some interesting new techniques mainly around the coating chemicals used and how they are "baked" into the product. Gin (who I have recently started selling for) also worked with a company called Myungjin who make parachute cloth/textile machines (lots of them for a very long time) and it seems all of these companies have made huge advances in coating types and techniques for application and the recent gains in textile attributes are massive. This in some ways is similar to what has happend with Allula where the result are next-level materials. So this new breed of materials have been tested for stength and porosity both new and over time with exposure to the elements (sun and water/washings) and the new materials are way way better, especially at handling degradation over time and with "washings". So this is one of the reasons Soul has come out with Soul v2 basically being same kite with new material; the improvements in durability (and performance) over time per weight make it a way better kite over its lifetime. But other designers have taken these new materials in different direcitons. Flymaax have used these new types of materials and used their connections with Gin Gliders and their fabric partnerships to build the worlds fastest race foil kites. But interestingly and relevant to this topic, the lowest they felt they could/should go is 28gsm for top and bottom surface and in a material that is probably the best fabric of this type ever produced. Also Gin Flymaax have created a high performance freeride kite the Spirit and their fabric choice per the thread on this forum is Dominico (who I think also make FS fabrics) and the material chosen is 32gsm which is also super light but very strong and non-porous. And note that through similar techniques to Kauper, Gin Flymaax got the spirit down to a weight close to the Kauper Falcon and much ligther than the Soul and Soul V2 but whilst still keeping a strong enough fabric appropriate for this type of kite. To illustrate the risks of going too light with a fabric by way of using less coatings my wife recently landed a newish VMG2 for a friend, this kite had been swum a few times but was low hours and less than a year old and as she grabbed the kite to land it for our friend (she swears she grabbed it normally like you would any normal landing) and her fingertips went right through the surface cloth... There was also an R1v3 in our club that was about a year old and you could see fresh air through the white part of the surface cloth of the kite, it had become like an actual tissue with similar strength...
Getting to the point, the Falcon per its website is using a 25gsm material from a company that has never made material for a kitesurfing kite before. So the questions I guess is whether they have gone too thin, and the answer to me seems to depend on how this material is made. To be that light and to be still durable it better have some amazing new technology used in its creation. A traditional 25gsm cloth would be porous in no time, like some dud paragliders and race kites that pushed the boat out too far with light materials and became widely known as terrible after a few uses (i wont name names but there are several race kites this applies to, beware of second hand race-kites, always do at least a kiss test). The Falcon website (which is pretty awesome) explains that the surface material used is Paratex D10 and that it is "highly coated with silicone on both sides", these are good indicators, early materials with single coatings mostly washed off after a few kite-swims, but it does seem that some of the other textile leaders like Porscher have gone with a process of double coating one side and Porscher reckon it works better. Flysurfer also worked with Dominico on some of their textiles and helped move the tech ahead with double coating processes and use of PU and silicone. But there is still some debate about D10 materials in paragliding forums and whether it can really become viable for every-day use being that light, I guess time will tell. Also the rib materials for falcon are 32g and 27g which is super light, but hey you can always fix them with sail tape if you rip them. For me having ridden the Spirits I think Gin/Flymaax got the design trade-offs bang on and they are only about 100-200g more than falcon, but I'd also love to ride a Falcon, I love ultra light kites/paragliders.
Note that kitech for the FRS faced the same trade-offs and ended up choosing to make a regular and ultralight version, the ultralight FRS uses 27g on upper surface and 32g on lower surface which takes more load and a mix of 27/32g for ribs. The 27g material kitech use is Porscher's Skytex 2 (I think they mean Skytex "Classic" version 2) which is a class leading material also used in race-kites with a double/twice coating process wihch I believe involves doing a coating process twice on the same side of the material saving weight but with amazing porosity results over time and washings. There is a graph of this material's porosity over time and "washings" somewhere, will post it when I find it if people are interested or google it, but this fabric is excellent. As a side note I also own a Halo 19m that has had plenty of swims (it was my sub 10kn kite) and now has similar porosity to a dish cloth.
There is a whole other discussion about AR but again I prefer a slightly higher AR and if you ride a Spirit or even a Soul I'm not sure you need much more stability than that, they are both rock solid.
Lastly on price I love the idea of a cheaper high quality foil kite (that's why I started my business). But the price for Falcon is similar to FRS and not too far off what i can sell a Gin Spirit for if someone asks really nicely