I'm very pleased with this mouthpiece. I own and play a Yamaha YTR-651 D trumpet. It is a top of the range vintage pro-level trumpet. I'd tried three different mouthpieces before I purchased the Yamaha 11B4 and all three had their good and bad points. Wish I'd purchased the 11B4 straight away. It's perfect. Seems to be very good quality. I like that the rim and cup are gold plated which is a much better feel on the embouchure. It's also great for ease of playing. High notes are easy. The tone of the instrument is much improved. It sounds better. Endurance is improved. I can't fault it. Would recommend it to anyone looking for a trumpet mouthpiece for a speciality trumpet - it does Eb/D and Piccolo. I haven't got an Eb Trumpet at the moment and my Piccolo Trumpet takes Cornet-shank Piccolo Trumpet mouthpieces so I can't give any feedback for those. However, in my opinion, it should be a really good mouthpiece for Eb/D and Piccolo.