The first video was the one Nimbus has shown at the Flight Sim Expo last weekend, where they demonstrate the torque difference to maintain the hover in ground effect (IGE) and out of ground effect (OGE).
It also shows the amazingly detailed rotorhead and superb animations. Nimbus seems to be doing an excellent work all around.
The second video shows the Huey flying around. If the flight dynamics are as good as the rest, Nimbus might just become one of our communities' favorite developers.
And that sound...? DANG!