The lane departure stuff on most of these dashcams really don't do much, unless you like to hear a lot of beeps. (Capture beat me to the punch on this..)
If you plug most of these dash cams into a switched power source, (Cig lighter socket that is only hot when the key is on) they'll turn on and off as you start/stop the car.
USB charging on the window mount? Not sure what you are after. You want to be able to charge other things?
I use various common 12v/cig lighter multipliers with a few usb ports on them.
It's nice to have dash cams and other stuff that take a somewhat common USB plug, as opposed to a coaxial type or other plug. If you're not tolerant of exposed or dangling wires there are simple to complex solutions for dealing with them. At the least you can usually find some crevices in the headliner to tuck the wires into.
I usually have a smartphone, tablet, and other stuff I want to charge as I travel.
Here's a Mobius C, with the add on capacitor, stuck in the windshield as I drove through Pai. The cam is on a suction cup mount, and the darker top of the video is picking up the tint band on the top of the windshield.
(in car audio covered up so the world doesn't hear the 'watch out for that motorbike/you should have turned there/we're lost' conversation.)
The mobius has decent video, small, no screen. It lends itself to a cleaner, discrete, install if you want that.