I recently got to ride the 5'7" 135L size, and I got to say that it definitely exceeded my expectations. Being inflatable I thought it would be bouncy and unruly. This thing actually has a pretty low amount of flex. Going to inflatable vs a normal hard board there are some definite pros and cons, this is what I noticed:
PRO
-Packs down into a super small well-built travel bag. Hard to get back into the bag, but its worth it for how much it packs down.
-Overall pretty stiff and rides well.
-Super safe option. This would be PERFECT to put your kids on for them to learn to wing.
-If you are between two sizes, go bigger. My normal wing board is 62 liters, so for me on this 135L board I thought it would feel massive. Because its inflatable and the mass is so low, it still felt like a small board. It was super stable and floaty, but still felt like a small board. Kind of best of both worlds.
CON
-Its still inflatable, so it does have more flex than even a low quality hard board. When I was holding the wing by the front handle and just pumping along on flat water, I could really feel how much pump power I was losing into the board. This makes the board not the best option for true performance ripping. For general freeride though just fine.
-The rails are big thick rounded rails that are sticky on the water. If you are going upwind and touch the rail to the water, it wants to suck you down farther instead of releasing.
-Be careful of sharp objects!!!
