As a long term victim of GAS, I have a drawer full of very good tenor mouthpieces; all being very nearly perfect for me.
This collection includes Jody Jazz ESP, a superb Pillinger copy of the "Slant Sig", Bergs, Otto Links, and Runyon Quantum...oh yes, let's not forget the vastly under rated Rico Metalite.
Since buying my RPC 115B, I have used nothing else. It has been said by another poster that this piece is a screamer...indeed it is; however, it will also subtone beautifully and has a thick, rich, low end. In short, it does everything.
I play in pretty well every style, ie. Rock/Blues/Ballads & Jazz; in fact everything except what I regard as the oxymoron "Classical Saxophone"!
The RPC accommodates all styles, is even throughout the registers, instantly responsive with a rich palette of colours.
All my other mouthpieces are destined for eBay.