Denis Wick 4880 Trombone 6AL

The mouthpiece took me a while to get used to. At first I was not pleased with it since I felt it was blowing back at me because of the narrower backbore, hence I recommend something more open (6BL) if you are switching from something bigger (I used a 4 before the switch).
In a few weeks the mouthpiece opened up nicely and is free blowing across the whole register. The gold plating gives it a soft attack and a warm, gentle tone. Also, I have noticed it sticks to my lips less than any silver mouthpiece I've played on before.
All in all, the 6AL is a terrific, quality made mouthpiece that will serve you for years to come.