When I plug in my 6D with the usb cable, it doesn't mount as an accessible drive (as a memory card reader does). EOS utility can access the camera ok, but there doesn't seem to be a way to view video directly without first copying it in, which takes a long time.
Is the 6D supposed to mount as a drive so photos and video can be viewed without first importing it?
No it doesn't mount as a drive.
You might try to see if you can just pull the file in using the Image Capture application on the MAC.
USB is indeed USB, however while the theoretical speed of USB2 is 480Mbps at max, the cameras certainly don't get close to this at all, can be as slow as 50Mbps for some, while a card reader is often faster.
For example with a class 4 SD card in my 5d3 camera I can get no noticeable time difference when downloading 100 image files than if I was using the same files in the same camera connected to the same computer but with a class 10 SD card. however put the class 4 card in a card reader connected to USB and then try the class 10 card in the same reader and the difference is huge.
depends on the card reader I'd think. Although I've been thinking about a USB3 reader.
The thing is, the card reader mounts as a drive, which allows you to play the video directly off of the card reader. No downloading required. So whether it's faster or not, the card reader is the only option if the camera doesn't mount, unless I want to just start the wireless and let it run for awhile.
09/26/2023: New firmware updates are available.
08/18/2023: Canon EOS R5 C training series is released.
07/31/2023: New firmware updates are available.
05/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
03/30/2023: New firmware updates are available.