We have 180+ controllers and 350+ APs.
I use Airwave for the monitoring and planning features.
It has been an invaluable tool. Prior to Aruba, each AP (Cisco) was being managed individually. It was impossible to get any sort of reporting or insight into any of the reported problems.
With VisualRF I'm able to properly plan AP placement, as well as go in and see what is happening. I use this on a daily basis as we continue to move from "wireless as a luxury" to "wireless as infrastructure."
Management enjoys the reports, and they provide me with the information I need to make sure we continue to provide adequate coverage and availability to our users. Previously I would spend hours (if not days) parsing log files and fiddling with scripts trying to get something that even resembled accurate information.
Now I can go in, click on a controller (or AP) and see exactly how many users are connected, any issues, as well as pull up historical data to see if any above average usage is a "one off" event or a new trend that needs to be addressed.
Edit:
I recommend watching this video from the Wireless Field Day - it should give you a great idea of the functionality of Airwave.
http://youtu.be/SkCWOJM5xZc