A big disadvantage when working with the Microsoft CRM SDK assemblies, is that you have to use dynamic entities most of the time. While the DynamicEntity class was enhanced in CRM 4.0 to make it easier to use, you’re losing a lot of benefits you had when using the web services:

• Type and property checking: You don’t know at compile time if your code is correct, because you are not using strongly typed classes and you don’t access named properties.
• Intellisense: because of the above, you also don’t get any context-sensitive help while developing in Visual Studio
• You have to use the more complex RetrieveRequest and RetrieveMultipleRequest messages with the Execute method instead of the Retrieve and RetrieveMultiple methods.

All in all your code becomes more complex and it takes more time to develop and test. The Code Generator module gives you back everything you lost plus some additional benefits:

• Works with the CrmService class and the ICrmService interface from the Microsoft CRM SDK assemblies
• Creates C# and VB.NET code
• Creates classes for all or selected entities, providing nullable properties for easy access
• All attribute names in each class are defined as constant strings, so you never have to look at CRM again to remember the correct spelling
• Creates enumerations for all picklists, state and status attributes
• Adds methods for easy use of the CRUD operations (Create, Retrieve, RetrieveMultiple, Update, Delete)
• Adds methods to change an entity’s state
• Provides easy management of all reference types (Lookup, Owner, Customer), e.g. you write account.Primarycontactid = myContact.ToReference()
• Adds comments to classes, properties and methods, which are available in Visual Studio through Intellisense.
• Allows you to create your own code generation templates. If you want some special methods in every class, then simply add it to the template files.

The Code Generator is limited to the account and contact entities when running the community edition.