As someone who, like most of you, scramble to try to get information on winging gear and find reviews somewhat lacking, I offer some information of boards I've owned and ridden.
Here is a list of the boards I've owned and ridden. This review isn't about volume but about other board factors.
Fanatic 5'4" 95L list $1199 straps
Fanatic 6'0" 125L list $1199 straps
FONE 5'0" 60L list $1479 no straps
FONE 5'4" 75L list $1499 no straps
FONE 6'0" 110L lsit $1629 no straps
Naish 4'6" 50L $1185 straps
Custom Carbon 5'4" 70L used $600 no straps
Alien Air 32L 4'6" $450 straps
The fanatic, fone and naish boards all had excellent design and were designed for winging. They all worked extremely well for that purpose. The custom carbon board I rode was shaped by a talented winger and foiler but lacked by comparison design wise to the other professionally designed boards. The slingshot alien air was by far the worst design wise, not even being designed to be used for winging.
I won't elaborate much on design of the naish, fone or fanatic. The boards were designed to be used for winging and to that end I would not venture to say one was any better than the other. They all performed as expected and I was happy with how each performed. They would all achieve a 10/10 for design. The custom board worked, but was off somewhat in the swing weight, plus knee starting was more difficult due to weight distribution limitations. I would rate the custom board at 7 or 8 of 10. The alien air was absolutely the worst for knee starting, and was similar to the others when up and riding. However, I must give it an very low score for design for winging because it really just didn't work. 1 or 2 out of 10.
The next rating system is for straps. Obviously the fone has no straps, so it scores a zero. The naish has straps but for the foils I ride they are not positioned correctly, so I'd give it a 7 out of 10 for straps. I do conceded that Naish boards are made for Naish foils, so remember this when mixing and matching foils. Not all foils will allow your feet to line up for different board/foil combinations if you ride with straps. The custom carbon also had no straps, so 0 out of 10. The alien air's straps were perfect, as were the fanatic straps, so both get a 10 out of 10.
Build quality. This factor alone I found to be huge, and a big deciding factor for me in the future. I buy all my gear thru Mackites, and they have an excellent guarantee progrem, and I know that fone, naish, slingshot, and fanatic, all stand behind their gear. That is a good reason to buy new. However, there is more to it. The fanatic I found to be very heavy, hoping that the extra weight was extra layers of protection. Not so. I've known 2 close friends now who have sprung leaks in their fanatic boards and are having to get warranty replacements. On my fanatics I found them to be very fragile, and the weight did not result in more reinforcement. It was just more weight, sadly. Due to their fragileness I would be very hesitant to buy another fanatic until their quality improves. The fones were a delight to hold and ride due to how light they are. Sadly, that lack of weight comes with a serious penalty - they are extremely fragile. Fanatic is fragile, but fone is extremely fragile. They ding far too easily. If you can baby your boards then this is acceptable. But I predict they won't last long or take any abuse otherwise. They had the best ride of all the boards I rode due to their lightness, but again, at a great cost. The custom carbon I found to be literally indestructable, something I appreciated the most. It wouldn't ding and you could throw the board around somewhat and it didn't mind or get dinged. The Naish was/is by far the most durable production board. I've never been a big fan of Naish until now, and I can say that their board is durable, which I appreciate. The slingshot alien air was fairly durable as well. I'd give the custom a 10 out of 10, the Naish a 9 out of 10, and the Alien Air a 9 out of 10.
Price. The price goes without saying due to its "self rating". I found the custom carbon to be the most bang for the buck. Second is the Naish. Hard to say which I rate third. The fone's are very expensive, and I have concerns over warranties on the fanatic. The alien air is a great price, but I really can't ride the board. So, my pick is the Naish.
I have a new Naish Inflatable sup/wing foil board coming in today which I'll review soon.
The takeaway: The major brands seem to be producing some wing specific boards that work well, very well, as designed. The deciding factors may end up being durability, cost, and straps. You can't judge a book by its cover! These boards are very expensivie and are quite an investment and so we want our investments to last for ourselves our for resale value. The custom boards out there seem to be much more durable - their build qualities are much better but they lack some in the design (which only makes sense since they are often one board at a time design and trial and error). And, boards that don't work for their intended purposes aren't worth anything, at least for winging.
I have not tested the converted race boards, something many riders around me are riding and is something work looking into.
I suspect that many of these issues will improve considerably in the years to come.