The Rough Rider

I have never heard of the Rough Rider. This is a pretty cool wheelchair technology. Sounds like it is ideal for many parts of the world. I like the front casters. I can see that they would be perfect in many countries were the infrastucture is terrible. However, I would think that they would decrease the performance of the chair. Would't it make it harder to push?? Wouldn't the long frame make the chair less agile? Would you use this chair?