Valuable Features:
It would have to be the ability to monitor services, devices, and operations for many devices from a single console leveraging a wide variety of Management Packs available.
Improvements to My Organization:
Ability for support staff to know when there is a problem, identify where the problem is, and figure out what is causing the problem, ideally before the users of the applications encounter the problems.
Room for Improvement:
If it could have SysLog capabilities and if the Microsoft Management Packs were out of the box instead of a separate download.
Use of Solution:
Our current project is still ongoing, its been at least 7 years.
Scalability Issues:
Yes, but only if you decide to integrate ACS with OpsMgr. Then storage could become an issue depending on where the customer believes the security logs must come from.
Customer Service:
If you have Microsoft Premier Support, then all is well.
Other Advice:
Understand what is critical in your environment first and what needs to be monitored.