1) SharpMap does not read .lyr files or raster catalogues
2) SharpMap v2 can edit shapefiles 0.9 cannot. v2 is at
3) There is no legend control, you bring your own using the map.Layers collection to drive your own UI
4) FeatureDataTable is derived from DataTable so you can do anything that you would be able to do with a normal DataTable. (in 0.9)
5) There are no specific functions for printing.
6) The model is open - you could create specialist layers for drawing overlays or you could render to an image buffer and then use the Graphics object to draw over the top
7) 0.9 is stable, v2 less so (if you go off the beaten track) but acceptable for many purposes - both versions are in use in professional applications