In my case, CIS's HIPS prompts don't seem to be too friendly when compared to, say Online Armor. However, the prompts have more options to offer flexibility for the user's needs.
CIS offers more options/features than other paid-for Firewall+HIPS, and with a great community to help you setup the needed configurations depending in your situation.
I experienced very little performance impact on the system. No noticeable slowdowns of startup, network, minimal CPU usage etc.