We have a number of VMware sites. They are small. Typically two or more Windows servers. Sometimes a copy of Windows 7 or above. If you need a Linux server, it works well. We have done this for a few years going back to v5.5. Most of our sites have updated over time and are on v6.5.
VMware has released v6.7. There is a problem. This is not a minor release. There are some issues. The point being, you should expect to spend some time in testing before moving to this version.
I found a couple of article on how to do the upgrade and at least one saying “don’t do it!”
How to easily update to esxi v6.7
Upgrading from esxi v6.5 to v6.7.