The most valuable feature for us it the granular, logic-based nesting of objects which gives highly customizable control over AAA for TACACS+ and RADIUS.
Device profiling for basic/intermediate NAC is also highly useful.
Providing granular control over which devices are permitted to join our corporate wireless network, as well as in-depth AAA (accounting, in particular) for TACACS+ sessions, is huge. We can refer back to these logs at any time, which are especially useful when we undergo organization-wide audits.
Having a global business presence, CPPM helps us to ensure all sites are compliant with a unified set of standards passed down from our corporate headquarters.
I've used it for just over three years.
I don't recall any issues with deployment.
I don't recall any issues with stability.
I don't recall any issues with scalability.
Technical support was not all that great, actually. They are responsive, but oftentimes are VERY reluctant to initiate a screen-sharing session or give in-depth answers. URL links to knowledge-base articles are very typical for initial answers, which (1) slows resolution, and (2) increases frustration.
It seems, in general, that technical support is more interested in closing new cases than they are in actually solving the root issues. 90% of the questions I’ve had I’ve had solved (for free, mind you, without any maintenance fees) using Aruba’s Airheads online user-based forums.
The solution was implemented before I gained ownership of it. I'm not sure of the history behind it.
Do your due-diligence in understanding how the product works before you deploy. CPPM (and many like it – Cisco ISE and ACS) are very complex in the way they are configured and operate.
If you can design the solution before implementation, you have a much better chance of scaling well, easily, and with little down-time as you grow the product throughout its life cycle in your organization.