The Lindberg 5CL is a good mouthpiece, but its sound did not impress me. It looks really great, and I had no problems with its narrow and rounded rim, which actually I like (some like it, others hate it). It resembles in size the Bach 5G, but it is most similar to the Schilke 51B. Of course, it is quite similar to the Lindberg 5CL too, the difference being mainly in the throat and backbore sizes (larger in the 4CL).
In terms of sound, the 5CL sounds very similar to the Lindberg 4CL, just a bit smaller in the low notes and easier/lighter in the high notes. It requires less air than the 4CL. Compared to the Schilke 51B, the Lindberg 5CL is very similar in shape, playing and sound, just a little bit more aggressive, metallic and with less core. It is also more difficult to control the notes (I don't think that it has to do with the rim, to me it seems to be a backbore issue). Personally, in terms of sound and playability I prefer the Schilke 51B, although I prefer the Lindberg 5CL rim. My general experience with the Lindberg mouthpieces is that they sound great in solo, but they do not blend as well as the Bach and Schilke mouthpieces in a horn section. That is a matter of taste, of course.