If you want to have a easy on easy off fairing to use with your Road King, the Hoppe is the way to go. I took mine off in 5 minutes the other day.
The Hoppe while a clean looking unit looks like an aftermarket item.
If you want to convert your Road King to an Electra Glide on a more or less semi-permanent basis adding in a bunch of guages with connectors for each wired into the bike then the Dragonfly is the product. This is not an easy on easy off unit, however, the Dragonfly looks like a factory installed item.
Hoppe Quadzilla - - - Steel mounting brackets, easy 30 minute initial installation of adappter harness ( three wires, + and - on battery terminals plus one connected to main ignition circuit ) attach fairing to windshield attachment points, plug in adapter harness, insert CD and away you go. On or off in 5 minutes once adapter harness is wired in.
Dragonfly - - - - - - Fiberglass mounting brackets. Lots of hours invested in setting up electronics in unit and if wanted adding guages. Amount of time in disconnect determined by how much is added to the unit.