Likewise, Palli 
(Avalor - Palli is the resident ReportViewer expert)
You can use either. It's a matter of preference. Main Strengths & weaknesses I've found:
- CrystalReports is weak on subreports (only Parent-Child, no nested subreports); whereas, ReportViewer supports n-Level subreports. This is a deal-breaker. I jumped ship to ReportViewer because I needed 3-4 levels of subreports.
- CrystalReports is weak on Excel exporting, whereas ReportViewer is much cleaner at Excel exporting.
- ReportViewer is weak on custom formulas; whereas Crystal supports as many custom formulas as you wish, which can even calculate against eachother. My workaround for this with ReportViewer has been to insert all calculated fields into the DataSet before passing it to the report.
- ReportViewer is weak on multiple DataTables. ReportViewer cannot follow DataRelations within a DataSet; whereas, CrystalReports can follow DataRelations & automatically filter related DataTables based on the relation. This is easy to overcome in ReportViewer, as you can manually setup the Filter on the related DataTable.
Hope this helps!
Ryan
PS. No, you don't need a wrapper for either of these controls. We've already done that for you.