Gerard, there are many people who have moved from CR to SSRS without a problem.

However, there are some features that have existed for a long time in CR and haven't found their way into SSRS.

For instance, you cannot keep a group together on the same page, if it would otherwise split across pages.

Additionally, SSRS cannot handle a stored procedure with multiple result sets.

The charting in SSRS 2005 is weak compared to CR. (The charting in SSRS 2008 is better).

Now, some might build dozens of reports without needing these functions. It all depends on the reporting requirements.

Most people move from CR to SSRS because of the licensing.

I've taught SSRS actively for almost two years now - while I like it very much, I still give CR the slight edge when it comes to functionality. If you're developing a smart-client type app, where reports run on the desktop, I say go with CR. However, in a browser-based reporting environment, SSRS is the better choice.