Ryan,
Let’s say Silverlight is totally different from Desktop; Silverlight is a compact version of the .NET framework which cuts some of the APIs; such as GDI+ stuffs supports. Also Silveright App runs as B/S structure while Desktop doesn’t. That means you don’t have much authority to manage something on client’s machine. So Silverlight Edition has more limitations than Desktop Edition.
Actually, Silverlight Edition contains a client control and server control which you can find more information in our quick start.
For the client side control which response for drawing on the client side. Compare to the Desktop, they both support Overlay, Tracking, Editing; but Silverlight Edition has more predefined map tools to use directly such as MouseCoordinates, OverlaySwitcher, etc. But the client control doesn’t support some features which we need refer to the 3rd part assembly such as RasterLayer and MsSql2008FeatureLayer; also we don’t support GDI+ drawing; but we have WPF and WritableBitmap instead.
We support rendering image on the server side as well. In this way, Silverlight supports all the features that desktop supports.
It’s hard to say the difference of the performance between these two editions. Because different overlay has different performance. For instance, Silverlight Edition has WmsOverlay while Desktop has WmsRasterLayer. WmsOverlay requests images directly from wms server while Desktop has some middle algorism to generate the images. That means WmsRasterLayer is slower than WmsOverlay.
The two versions have a same sample which specifies the drawing performance between Silverlight Client drawing and Desktop drawing. Please refer to the RefreshPointsRandomly.xaml in Silverlight Edition and RefreshPointsRandomly.cs in Desktop Edition for detail. After running this sample, you can know better about the drawing performance for Silverlight and Desktop.
For server rendering, silverlight has the same performance as the desktop.
Hope it helps; let me know if you have more questions.
Thanks,
Howard