Many people here in Hawaii spotted one or more of these balloons a few years ago. I guess now we know what they likely were!

I also wonder about the wisdom of waiting, but perhaps damage to the payload would be minimal if dropped into the ocean rather than on land with the force of impact damaging the evidence. I sure don't know, but have to hope the choice was the right decision and that whatever information gathered was stored on the device, not beamed somehow to China in real time. Interesting stuff.