Not much. I've heard that the shank of the mouthpiece won't fit certain cork diameters, but I'm not so sure of the sound qualities of it. Quality control of mass-produced items like the Rovner products isn't very great.
hey man - you posted on my question about a year ago and I didn't get a message that you posted. It was about the Rovner L9 metal alto mouthpiece. It's a Deep-V. Do you know much about it?