I don't know what the prototype sounds like. To me the sounds are similar to the soundsets for a GG1 or EP5, that said, it is 100% better then mentioned sets. The sound is cleaner, able to lower engine sound while maintaining a loud horn and bell and no crew talk. Better sounds are coming are way. The only problem with mine was a few cosmetic details where missing or broken. Not enough for me to send back.
Bill