It's hard to describe... basic in my opinion is a waste of money go at least for advanced.
Advanced enables historic data collection and report generation - so you'd see in much more detail what is going on in the network and not only what is going on right now but also yesterday/months before.
That gives you much better troubleshooting tools and you'd also plan for the future if you run i.e. a report for bandwidth on the uplink for the last 6 month.
You'd request a demo via
http://extremenetworks.com/request-demo/
I hope I'm right but that should be an remote demo with an Extreme expert.
In this 30minutes demo you should get an very good overview of the product and how it could make your job of managing the network much easier.