One huge advantage of making the jump from XNA4 to SharpDX (and DirectX 11) is the huge number of new texture formats I have to play with. Not only can I use the BC* textures (DXT1, DXT3 etc) but I can now much better match my textures to their usage.
Visual Texture : BC1_UNORM / BC3_UNORM
Heightmap : R32_FLOAT (probably way too precise)
Planting Mask : R8_UNORM
Normal Map : R8G8B8A8_FLOAT
Also the ability to save as UINT format for most textures and use the Load instead of Sample gives me an ability to do pixel perfect texture sampling with ease.
Phillip Hamlyn 