I'm not sure why these are being described as "wild looking" - they just look like a larger version of the engines you get on smaller turboprop planes - is it just me?
To me, propellers feel like old, slow, noisy technology, even if they are efficient at keeping small planes up in the air. I'm sure they'd eventually look normal on jets, if this technology works out, but right now they look very unusual.
They are indeed very, very noisy - inside the cabin, you almost have to shout to be heard. It's a strange kind of loud though, in that it always seems to make me sleepy!