Strengths: Never needs spoke tensioning. Extremely durable. I've logged a lot of hard miles on this wheel and it still looks new. Feels stiff.
Weaknesses: If a spoke ever breaks the whole wheel is trash. Wheel is not perfectly true but cannot be adjusted. It's my understanding that few of these wheels are perfectly true. My wheel is off by only a small amount.
I've used an H3 rear wheel for at least three years now as my primary race wheel for long distance racing. 24 hour races, Race Across Oregon. Also for randonneuring. The brake area of the rim has worn very well even riding in the rain. I can't explain why it hasn't worn as fast as my other rims, but it hasn't. It also has remained true. But it better because It cannot be adjusted. Hub maintenance is very easy and HED has the parts for a rebuild. The wheel is a bit heavier than some of my other wheels but it feels fast. It also feels stiff and smooth rolling. The bearings on my wheel are adjustable and easy to grease.