I think you'll get a lot of benefit from having an AirWave server in your environment. Your main concern was for historical data logging which AMP can do. The historical data covers your own network devices, clients (active and inactive), rogues, reports, radius / ARM / IDS events, device configuration, guest users, etc. Each retention value can be fine tuned to keep a longer history for the items that are more important to you.
For user perceived issues, you can configure the system to send alerts for when devices are down. You'll also be able to see the signal and usage of the user during the duration they were seeing problems. Using reports, you can track down if a user was on an overloaded AP, and additional trending.
My response has a weighted bias toward being pro-AMP, but seeing is believing so I'd suggest taking AMP for a test run. Here's the informational page on AirWave on the Aruba Networks site: http://www.arubanetworks.com/products/management-security-software-2/airwave/. Also, here's a link to the Eval Request: http://www.arubanetworks.com/cdw-eval-request/.