We are looking into upgrading our Campaign. What are some of the key benefits that v7 has over v6? How do the two version differ other than bug/issue fixes?
The main difference between v6 and v7 is that v7 offers a bridge to Campaign Standard with:
You can learn about the ACS connector here: Principles and data cycle
Let me know if you need more details.
In terms of Security, a major flaw was discovered in v6.1.1 b8770 and below, a patch has been released, but this alone should be a reason to upgrade, along with loads of bug fixes, new features, security enhancements.