Is Wi-Fi on the 6D as bad as on the G1X??
Once you manage to get around the braindead Canon limitation (you must install a virtual wifi access point on your pc to connect the camera) it's quite ok.
The limitation is that obviously without a real antenna the connection strength is limited when a wall or a long distance is involved, and even @100% speed I'd rather put the sd card into my laptop than to wait for the wifi transfer.
However " gift horse and such" ... and I recon it's invaluable once you use it for certain wildlife setups or quick blog uploads for journalism. For longer runtime, an external power source or grip is advisable though to extend the battery time.