I have two of these decoders.
They are for the second run of the Walther's C-Liners that were DCC ready; the box says Walther's not Life-like and the engines came with Accumates instead of Rapidos.
The sound is generic and there is no way to download a sound file into one, however these include 4 different prime movers sounds (MRC's first diesel board had one, and more recent ones have had 2 - SD45 & MP15). Based on the MRC ad, the 4 prime movers in this one are the ALCO 244, SD60, SD70 & EMD 567B.
My opinion is that the sound is a bit weak; they might be okay for home use but aren't strong enough for trainshows. I played with my pair this weekend at Bedford and could barely hear them. I'll bring them to Timonium in October for those that are interested; I may play with them between now and then and see if I can improve the accoustics.
Tim