My choice
I think the small Wind Ladders would be good for a pilot project. But ultimately I think the bigger version is better. Reason being, the bigger ones would be spread out more and so be less of an obstacle to ocean shipping, and visual aesthetics. If they are far offshore then even at a height of 3600 meters (~12,000 feet) they would still be below the flight path of large aircraft that cruise at 2- to 3-times that altitude. Small aircraft with lower cruise altitude don't normally fly far from shore, so they wouldn't have any problem either. There are stronger winds offshore anyway, so this is an ideal solution.
The bigger... the better!