I find the interface feels more modern and interactive, I didn’t like how static PiHole felt with adding to a list then manually restarting Gravity.
AGH has support for more list types, it has more features built-in, such as DNS over TLS so I can use it on my phone even when I’m not home.
And personally I feel like its less buggy, I’ve never encountered a problem on AGH, whereas I did on PiHole.
That would be something you do within the Client Settings page. You can have custom settings that are separate from the Global Default.