GenSight Enterprise Portfolio Management is well suited for companies that want to implement top-down portfolio management capability to analyze risk vs. value, prioritize, optimize balance, maximize value and ensure strategic alignment of the global R&D portfolio. It may not be the best fit for companies that want to implement a bottom-up project management capability to track the status of programs and milestones.
Microsoft Project Server I believe is best for any organization from small to large. As I mentioned, it is a little pricey so I would do research into alternative software and depending on your needs maybe look at all options, competing software. This is a tool with a learning curve and some may not be able to easily navigate this software. There isn't really great training, resources available for this tool however there are some free YouTube tutorial videos. This is great for cross company, department project management, sharing, managing of projects and timelines.
Project planning: tasks assignments, resources allocation, progress and cost tracking. The Server version is the natural extension of the Microsoft Project standalone.
Provides one place to manage all projects, accessible by everyone in the team. This opens the plan updates to team members as well(on their tasks), as opposed to being done only by the project manager.
Reporting and visualization - resources utilization, timeline etc
The integration with the Microsoft Project standalone: if you don't like the web version, you can download the latest and work locally. When done just sync it back to the server.
One of the key advantages of Microsoft Project Server (MSPS) is its ecosystem. It gels very well with SharePoint, Office, Office 365. The support from Microsoft is also a key driver and they are very experienced and many ways to resolve issues. Also, Microsoft has bridged the gap of cloud offering from other competitors by providing Project Online. It is an offering through Office 365 which is very lean and low maintenance.