Just to add to this thread: I am not sure yet about the dynamics of the SM3 in terms of 'soundstage', but everything else is quite.... spot on. They are linear and truly incredible with great control.
They are also pretty well driven even without an amp, possibly to the most incremental of advantages. Obviously, they weren't just designed, but engineered to sound the same or as close as possible to the same from any source.
The only problem I have with earphones like this and the UM3x is the build which belie their price... nothing over 300$ should have tiny plastic sound tubes or plastic shells, especially for stage use where things get tugged and destroyed pretty quickly. Of course, it is a market dominated by one or two companies who both use cheap plastic bodies, so... it isn't anything but a shame; it's just sad that cheap is the status quo.