The most valuable component of Opsview might be the very good web GUI. It provides a great overview of all hosts and services; furthermore, adding new monitoring targets and modifying existing configuration is possible. The web interface is powered by at least one database which makes it easy to backup. In addition one might take note of the API which at least allows automated configuration.
Improvements to My Organization:
My company never used Opsview for themselves, but we provided it for many customers. Before using Opsview, they complained about chaotic web interfaces and nonsense monitoring messages in their old solutions. Afterwards, they were impressed by how easy monitoring could be, and they no longer had to edit large text files in order to configure hosts and service checks. Instead, they simply started using the Opsview web GUI which is also very self-explanatory. So no long introduction was needed.
Room for Improvement:
The API provided by Opsview is, compared to other monitoring solutions, not state of the art. It would be great to see that more efforts would be put into this part of the product. Furthermore I would love to see support for more database systems which are needed for storing configuration stuff and data.
Use of Solution:
I was using it between mid 2012 and the beginning of 2014. The foundation and the architecture haven't changed much since then. I worked with Opsview before the pro version had more features than the free community edition (e.g. Opsview Core 4). It was always running with Ubuntu 12.04.
Since Opsview heavily relies on MySQL and InnoDB, backups or large installations can be slow. You will need to put a lot of time into tning your database in order to keep it performing well.
It was easy since Opsview provided a working Ubuntu package, and a good how-to.
We automated the deployment, and did it ourselves, so no consulting was Needed. When implementing Opsview, one has to make sure that the VM OR hardware beneath IT, is powerful enough, and that MySQL is configured the correct way.
Cost and Licensing Advice:
Large Opsview setups come with high licensing fees. I find them to be too expensive, but that is only my opinion. There are not many different licensing models, so if you go for an Opsview installation, make sure to talk to your Opsview partner or the vendor and make sure that you get the best prices possible. Only use the core edition for trial setups, not for production.
Other Solutions Considered:
Well, if you are ready to spend a lot of money and time in getting a large system view installation up and running (in a performance way), Opsview is THE solution which covers most requirements you can possibly have. But if you want to rely on open source software, which has no license fees or feature limits, I can recommend CheckMK, Shinken and Icinga2. I used CheckMK and Icinga 2 for monitoring projects since the end of 2014 because I prefer limit-free open source software over commercial software.
It is a great product, and if you accept that you have to use MySQL as the database system you will definitely like it. If your installation will cover more than 100 hosts, you should run Opsview on bare-metal.