I have fitted a fair few to bikes and old cars in my day. I have always opted for the relay approach.  The power for the coil comes from the ignition switch / front light via a low rating fuse. The contacts of the relay are connected to the battery via a fuse higher rated fuse. This method allows for isolation from the bike electrics. The switching of higher loads and the prevention of draining the battery. If you want to be able to use the socket without the ignition you can fit a switch under the  seat to connect the coil direct to the battery and not the ignition switch. This method (without the switch) also works well for heated grips too.                                                                                                                                                                              

You must have the desk fan turned up high!
;)                                                                                                                                                                             

eh??                                                                                                                                                                             

Or god forbid .. he`s actually riding the bike .. lol                                                                                                                                                                             

One thing you need when fitting the socket is time, get a brew and think about where to situate it, how to wire it etc...

I have had the best quality "waterproof" ones on different bikes and they all the are not waterproof when I forget to close them.

Imho, fit in a place that will protect from the weather (under seat/behind panel etc...)
Wiring best job you can, route it safely, appropriate fuse, switched/relay etc...

I'd isolate it in some way either through a switch or switched live.

This is one of the few mods I will do but it really saves the day for sat nav/phone/music etc...