It is hard for small teams to afford the tool. I guess you can use TeamViewer for calls as well, but I never figured it out as we are pretty much embedded into Slack :D Also the price is rather steep. While on a call it gets tangled up with the call Skype/Slack/Hangouts etc) and creates very irritating screeching noise and/or feedback.

To be honest, the sound settings is a little confusing to set up. The remote access without assistance feature is especially helpful for a project manager who needs to maintain assests in separate locations. TeamViewer has proved to be the most stable tool for that. Being a remote employee, I have to use PCs all over the world pretty frequently. The file transfer feature works like a charm and is very secure, if you are worried about privacy. This is the most stable remote access tool I have tested, and I tested an awful lot of them. Do keep in mind, to get the best out of this tool, you should have a stable network on both ends. There were some issues with network, but that is not TeamViewer's fault. In my years of use, I have only seen it fail a couple of times. This is a robust workhorse for any and all remote assistance, resource maintanance tool.

Teamviewer pricing