I'm working professionally on a photo setup, using a computer, taking photos, and uploading to an Internet site.
Everything works with a Canon 5D mk2 and custom made software written in python using the gphoto2 library on Linux. I'm using it on medium-quality mode (jpeg, around 1 MB per photo) because photos are for Internet, and it's too slow with higher quality.
I have to duplicate the setup for another location, and I'm wondering what camera I should buy for around 1k €. I could go with a second-hand 5D mk2, which is on the budget, or a new prosumer model. New Nikon, Canon, and Sony cameras seem to be well supported by gphoto2, but I was wondering if one of these brands or models is better at tethering. Maybe with improved shutter speed, transfer speed, USB stability, or USB3. I didn't find any comparison on the Internet regarding tethering.