SCOM's greatest attribute is that you can customize every monitor to specifically match the intended system. For example, you can monitor two servers for high CPU usage and customize it so one alerts if it goes above 95% and the other only alerts over 98%.
Improvements to My Organization
If SCOM is implemented correctly, it can take away the need for administrators to constantly monitor things or perform health checks. SCOM can be set up to alert when an issue occurs and SCOM is often easy to link to a ticketing system so a ticket will be generated automatically when issues occur. SCOM can even be set up to send emails/SMS when a problem occurs in your environment.
Room for Improvement
The System Centre Operations Manager (SCOM) is great at alerting you when something breaks. It's not so great at reporting. For all of the information that SCOM collects and stores it has no good way to put this information into a useful reporting format. For example, it would be fantastic to be able to have a historic view of the memory usage on a server to assist with pinpointing the root cause to the issue.
Also, SCOM comes with many built-in monitors. Anything that isn't already there can often be add by installing a management pack. These management packs include a heap of monitors for a specific item (EG exchange). The main issue is that by default most items alerts are enabled. This means when you install SCOM or add a management pack you will need to tweak all of the sensors or you will be over run with alerts. It's a turn off what you don't want situation rather than, the more sensible, turn on what you do want.
There were no issues deploying it.
There have been no stability issues.
There have been no issues with the scalability.
Customer Service and Technical Support
Microsoft offers many partnerships to businesses. These partnership agreements can get you some great discounts on software/support. To become a Microsoft partner you often only need to have staff with Microsoft certifications. The more certificates you have the better your partnership. Microsoft are great to call for support as they have a wealth of knowledge. They may not always be the most helpful, but by logging a ticket to Microsoft you will often get your management temporarily off your back.