I've been using a Deg 6V mouthpiece, I don't remember where I bought it from, but it was online. I like it alright, but I just recently bought a new UMI 1736 from wwbw.com to try out, and so far I like the sound I get from the UMI better. I feel like it's a little warmer and more "melloey". I haven't gotten a chance to try it outdoors yet, but so far I like it. I also picked up one of the Kelly 6V's at the same time. I haven't had much time to work on it, but so far it's a tad bit stuffier than other 6 and 6v's I've tried, but all-in-all, it's not too shabby for a plastic mouthpiece. It still has a fairly nice tone. Seems like it would be great for cold weather playing (wish I had it when I was in college, I'll definitely be using it when I go back to play at homecoming in the fall), and it seems a bit softer on the chops. But please, please don't use a trumpet mouthpiece on a mello....you get a bright, unpleasant tone that doesn't blend well in the section. If you're switching from a trumpet mouthpiece, you may feel like you get a fuzzy tone at first, but you will get used to the piece after about a week of play, and your tone should improve.