Now I develop under Visual Studio 2005 and I use only Microsoft report system.
Those are the benefits I found:
- xml structure, so you can programmatically modify report structure;
- built in support for DataSets as data source;
- good parameters system;
- much faster than CR in rendering (i have reports > 1.000 pages).
Microsoft report system have some never fixed bug, as visual studio 2005, but for my experience is much better than Cr.