I play a custom Cal. model. It has a copper 5 1/4 inch bell, Sterling Silver Lead pipe, and two slides (waiting on a sterling Silver Slide). I had the modular Cl. for some time, which is a light model. They play very freely and have a great sense of feedback. I used Mt Vernon Style bracing on my horn, just to add some security. The Sterling Slide is a prototype, and when I tried it out I was very pleased with its response and overtones. My horn plays in a lead setting just fine
Several of the NYTC guys play the Cal light and sound great. Where are you located? IF you are near NY Rayburns has some horns in stock and I bet Felix would even meet with you. Send me a PM if you like and we can talk in more detail.