Microsoft CRM is a great product, but we need to set realistic expectations while making the evaluation decision. Like most technology products, it has its own strength or weaknesses.
First we should understand the philosophy being Microsoft CRM. Microsoft CRM does not compete with a Siebel CRM on functionality. It has very limited functionality with an emphasis on ease of use. Hence comparison with Siebel on functional points and industry integration would be useless.
Microsoft CRM is ideal for organizations with an existing Microsoft Stack Windows Server, AD,SQL Server, and Microsoft Office). The USP of Microsoft CRM is the integration with Microsoft Office in general and with Outlook in particular. Salespeople love to use Outlook, and the CRM Outlook client ensures that they have access to Microsoft CRM from within their Outlook.
Microsoft CRM also scores on Ease of Use. The Microsoft CRM UI is consistent with the Microsoft Office Outlook interface (and now most members of the Microsoft Dynamics family adhere to that look and feel). Users new to Microsoft CRM would find working with it a breeze if they are used to working on Microsoft Office.
Microsoft CRM is highly customizable. Anyone who has tried customizing a Siebel or Oracle CRM would love the simplicity of customization on Microsoft CRM. But obviously, there is a tradeoff between simplicity and depth of customization. There are certain limitation s the Microsoft CRM SDK imposes on certain types of customization.
A good Microsoft CRM consultant would be able to provide solutions that minimize customizations in Microsoft CRM, as it is a very costly affair to maintain and support customizations for an organization in the long term
To summarize, Microsoft CRM is a great product if you are a Microsoft shop, and are looking for a low TCO, simple to use CRM system with limited functionality