Microsoft SSRS biggest advantage is its ability to integrate with other third party components. You could integrate it with Share Point web part or you can access it from a Web browser, depending on your existing scenario you don’t need to change much to be able to integrate SSRS with your existing application. Microsoft SSAS offers low cost BI solutions comparing with IBM Cognos, licensing for SSAS is core-based or you could opt for server + CAL-based license which is very low in comparison with IBM Cognos. Microsoft SSRS & SSAS suite is uncompromising when it comes to performance. It provides very high performance and it could be connected to many different data sources. It requires very less time to build Microsoft SSRS & SSAS solution.
Microsoft SSRS is unable to provide a mechanism where poor performance reports could be prevented to run on production environment. In case if a user creates a report which can cause huge impact on server resources / performance it should not be allowed to run on production server during normal working hours. Alternative that is provided is to use subscription option to deliver reports to particular directory or email them at scheduled time (preferably non-working hours).Microsoft SSRS does not offer any interoperability with Andriod or iPad at this time (need to consider this if you are planning to develop reports for these environments)
Microsoft SSRS & SSAS suite is very easy to configure and maintain. You don’t need any license if you are looking to try out Microsoft SSRS; you can simply download and use Microsoft SQL Server Express (with Advanced Services). You can create dashboards, drill through reports, charts, graphs, maps, dynamic grouping using Microsoft SSRS.
It offers a very vibrant MSDN community along with Microsoft support staff for assistance.