We work with Red Paddle Co in NZ, where they are by far and away the best selling inflatable brand. We've been working with them for 5 years now, and using them in our SUP school throughout, where kit takes a lot of abuse, and they never cease to amaze me with their robustness, but also their performance.
Over the last 5 years I have learned a great deal about inflatable SUP construction. And I can offer a few definites, as well as a few opinions.
1. The RSS system (the battens that slide into the side pockets on the more performance-orientated Red models) do indeed set RED apart. No other brand has this, it is patented. And it makes a HUGE difference in performance. Red modestly claim it makes the boards 40% stiffer, from our own measurements it's nearly 60%. And stiffness is everything in inflatable paddleboards. So, in pure simple terms - a Red inflatable board with RSS is more than 50% stiffer than any other inflatable board of the same size. And that is pure performance.
What this means in practise is that Red can make inflatables that are 100mm thick, but are as stiff as the inflatables from other brands that are 120mm or even 150mm thick. Because this is the trick that many inflatable brands are using nowadays - if you make an inflatable thicker (from top to bottom) it increases the stiffness. But, making a board thicker also increases the windage, decreases the grip, makes you more top heavy, and massively decreases the surfing potential. You don't find solid board manufacturers making boards super thick, (except in specific race designs), especially around the rail area. So it's not a great thing for inflatables either.
So if you're looking for an inflatable to surf on, Red are way out in front, because they can produce relatively thin boards that are still stiff.
Likewise, in racing terms, the Red Elite raceboards, with the extra stiffness from the RSS battens are seriously fast. We just had the NZ National race champs here. Lots of people entered on Reds, competing directly against other 12'6s in the 12'6 class. There were Reds in all the races; the 4k, 8k, and 15k distances, and the technical (BoP) racing, and many placed really well. No inflatable from any other brand even raced - they would have been nowhere.
So, just because of RSS, Red do clearly stand out from the rest. But also when you look at what else you get in the package. Red were the first to offer a decent bag, and their bag is stilll way out better than any of the others. And then the new Titan pump - again, just soooo far ahead of any of the other brands. Especially if you're pumping up one of the bigger boards, like a raceboard.
There are significant differences in construction too. There are indeed only a few factories producing inflatables, and some are producing boards for literally dozens of different brands, and it is indeed pretty much the same board coming out each time, just with different graphics. However, Red pretty much have their own factory now, a purpose-built new plant in China. And as far as I'm aware, they're the only brand that actually has full time staff on site (in China) the whole time - other brands simply place their order as an OEM process, and don't oversee it at all.
Each inflatable SUP factory has a signature way of building their boards. Once you've been in the inflatable game for a while you can instantly tell which factory a board comes from, because of various signature aspects, one of the most important being the way the rails are built. The 'woosung rail' is different to the 'leewards rail', is different to the 'infla rail'. And the rail is pretty critical, as it's where the vast majority of inflatable construction is going on. The infla rail construction technique, as used by Red, Fanatic and RRD, is way more sophisticated than the other methods, and gives a whole lot more reinforcing too.
I could go on and on. But ultimately I think it all largely comes down to one 'cultural' difference, above everything else. Red only make inflatables, and are just totally focussed (indeed, I would say obsessed!), with producing inflatables that are as good, if not better than solid boards. Whereas brands that make solid boards AND inflatable boards are fundamentally compromised - if they make their inflatables better than their solid boards then they won't sell any solid boards! And because Red essentially have their own factory, and are now very much the biggest inflatable brand in terms of global sales, they have the infrastructure and funds to develop and improve each aspect of the process on a bespoke basis. Other brands have to simply take off-the-shelf components when it comes to valves, fittings, pumps, etc. Red are doing enough volume to be able to develop their own, which just increases the gap between them and the rest even further.
It was quite funny this year, watching a whole lot of the relatively new inflatable brands, proudly talking up their new double-action pumps. Whereas the likes of Red, Uli and C4, who have been in the inflatable game since the beginning, had all been there, done that, several years ago, and knew just fine that double action pumps are really not the answer for inflatable boards at all. Which is why Red have spent the last 2 years developing the Titan pump, a completely new (and genius) way of looking at inflatable pumps.
If anyone wants a bunch more info on inflatable construction, the different types dropstitch, rail manufacture and stuff, check out the construction pages on www.inflatable-paddleboards.co.nz . Yes, it is a Red promo site, but it's all hard info, and hopefully of use to anyone looking for an inflatable, whatever brand they're considering.