I laugh at the "quieter than helicopters" claim.
no doubt a comparison could be made that technically my neighbors 2009 Harley Softail is quieter than his highly modified 1000 GSXR...its really pointless because they're both annoying at hell at any time of the day
these uber contraptions will not be quiet. They will be beyond annoying. And people will tire of the constant drone in very short time.