 <p>The SDF classes aren't designed to be "better" than the CF classes - they are largely an extension of the CF-supplied classes. In many cases they provides methods, properties, etc. that the full framework may have but that the CF omitted. </p> <p>Obviously that's an over-simplification - for example the entire OpenNETCF.WindowsCE namespace is purely features that don't exist in the FFx or the CF, but as a general answer, that's how it works. </p> <p>The SDF is not a replacement for the CF, it's an extension of it.</p>