I wanted to see different views / opinions on this.
I've got Jquery invoking a function through ajax. It loads data two ways:
The ajax script loads JSON data from the same server, then uses JS to parse it and append it into html.
The ajax script loads complete html / script set up directly via that php script that's called and then JS appends it to html div.
I'd assume #1 is faster since it's loading a basic JSON array then uses JS to parse it and append to html.