I have not had much success with any of the PocketPC emulators over the years other than a short run with MameCE a long time back. PocketNester seems to work well, Roms do need to be located in the main memory, i.e. My Documents folder or something, as I cannot seem to locate them from the storage card. Speed is fine and sound perfect.
http://pocketpcfreewares.com/en/index.php?soft=670
Youtube video link (sorry about the squished video... didn't reformat from portrait to Landscape before uploading)....
http://www.youtube.com/v/q0REP1sDeVw
Total waste of time..... but hey... that's what this forum is for then isn't it.