Biggest pain points when collaborating with CAD?

Hi all. Industrial Designer here. Curious what sort of solutions you guys use for project collaboration, and what your pain points are?

I use email, web conferencing and phone calls. Pain points are scheduling conflicts..

As Kelly said above with the addition of Buzzsaw/BIW. The pain points for me are when one of the companies refuses to use mainstream, cross platform software (damn hippies!). We either have to try to reproduce their drawing or give ourselves heartache in converting the .pdf files.

Recently I started sharing solid works files with a client. it has a pack and go function that works, mostly files are pretty big so we use Google drive to trade them. Still we have to resort to Skype and figures drown on paper held up to the camera sometimes :)

Interesting. My usual problem has been transferring files over and versioning. We would do a pack and go and have a centralized server, but it was always a pain once someone else started working on the project - it would take them a day to get up to speed on the model, and if we were working concurrently it was a huge issue because we were juggling multiple files and making sure everyone stayed up to date.

Thanks for the answers so far though. :) They're helpful, I'm trying to build a list of feedback from industry professionals that I can forward on to other people in our company. It's not CAD, just rendering, but we render CAD models so there's a lot of similarities in the challenges faced.