Smart move, so you can design with either 3shape or exo. Which one do you think is more user friendly?
I am not a professional CAD/CAM worker but from my experience, both of them were all user friendly, I cannot say one of them is superior than other.
However matching d2000 and exocad doesn't look to be a good idea.
3Shape doesn't sell d2000 without dental system, so if you want to use d2000 with exocad then you need additional budget to buy exocad.
And as far as I have experienced, d2000 is really nice scanner, my DT didn't make die since the first day of scanning with d2000, 'cause it has scanned every corners of gypsum casts without die scan until now.