I like Dan's question. I remember Dan's kite snowboarding stoke from ten years ago by the way...hi Dan (you probably don't remember me).
I haven't flown my Flexifoil Blades on the water in a while but I hope to again soon. I used my B3 10.5 as my ultimate light wind kite until I finally picked up an SA2-19. I could squeak upwind in 8 +/- 1 kt but the SA19 is significantly better.
Obviously, a Flexifoil Blade in the water has an extremely low relaunch rate. I swam in a couple times every year out of 60-90 days on the water. If a Blade user were dumb enough to ride out farther than he were able to safely swim in (with no PFD) the kite sure won't help the rider get back in. These are issues of inconvenience and not safety (unless the rider has really lousy judgment).
If the wind picks up like crazy, there is no safer kite to drop in the water. No worrying that the kite will blow somewhere and hurt someone or get torn up. Get it wet and it will stay down.
In a really horrible launching and landing place, the Blades pop up really easily and you can land them anywhere. At the water's edge, in the back of a truck, on the grill of a car, on a porch, in a bush, on a tree, on some grass, in front of a trash can or volleyball pole, or even your child standing on the beach. I've done them all. They don't get destroyed easily and they don't hurt the things (or persons) on which they land.
In offshore winds I always enjoyed my Blades. No leash. Jump and spin all you want. If for some reason you were unable to stay upwind just put it in the water, roll it up (from the trailing edge only) and wrap it in your shirt or harness and swim in. It will never pull you out to sea and won't blow away, even if your lines break. An open cell foil and a "disposable" plywood board were my typical preferences for strong gusty offshore days. I never lost a board and never had to dump the kite to get back in, but it gave me peace of mind to know I could go out in those conditions and not worry about losing expensive equipment.
There is no kite faster and easier to launch and land than an open cell foil (especially a 2 line although I prefer depowering 4 line systems unless I am in the mood for more of a challenge).
In the early days, the guys who pulled out a Blade 4.9 or 3.3, or an F-One ATK 6.5 were guys with a serious go-for-it spirit. Seemed like every good rider had a 4.9 hiding in their trunk or under the seat of their car.
I used my own mods, especially the loco-blade depower mod which I posted on the foilzone and maybe on kiteforum as well. I had awesome depower and a really user friendly kite with a bit of decrement in low end raw power.
I will be using my Blades on the water again as they are really fun and offer something unique.
From my standpoint, flying an open celled kite requires the a commitment to keep your kite in the air. Paragliders, hang gliders and airplanes are flown with the same discipline. I don't drive my car with a willingness to crash it a few times an hour and I don't ride my bike that way either. If a person is willing to COMMIT to keeping the kite in the air and is willing to face the no relaunch consequence (I probably had a couple swims a year) a nonrelaunchable open celled foil offers a unique kind of safety, convenience and satisfaction. It is a little bit like using a wakeskate over a wakeboard with boot bindings. One of them takes more discipline and is less forgiving of mistakes but for a small number of people is really satisfying and fun in its simplicity and challenge.
If it weren't for my Flysurfers I would very happily do almost all my kiting on my locoblade modded 10.5 and 6.6. I would have a few swims every year and would spend zero to 10 minutes a year on repairs. I am completely willing to put up with the drawbacks in exchange for the advantages. I prefer my Flysurfers for a number of reasons but I will always love the nonrelaunchable foils.
There are a lot of ways to enjoy being pulled by the wind over the water. Each has its own unique advantages and disadvantages. I enjoy this variety while others do not. Open cell foils with their obvious disadvantages have many (not so obvious) advantages in convenience, durability, reliability, versatility, personal/public safety and minimal size & weight to make travel really easy. In general, I enjoy whatever am fortunate enough to experience.