We have some info in our Q&A section on mpcs, plus there are sites like Theo Wanne's Saxophone Mouthpiece Heaven that have a wealth of info on the subject. Learn the parts of a mouthpiece and how manipulating each influences the sound you can expect it to achieve. Once you understand that you can tell by visual examination generally what to expect from a given 'piece. It's a lot like looking at racehorses, I admit - some will surprise you both ways ... but your misjudgments can almost always be traced back to something you did not consider in your initial analysis. Here's a link to a good mouthpiece diagram.

As you explore the subject of mouthpieces keep in mind that the trend over time has been to make both saxophones & their mouthpieces generate brighter sounds. Sometimes this is intentional (bores & tapers in the instrument body) and sometimes unintentional (use of lighter & thinner metals, usually to cut cost). We can get into a lot of theory here & chew up pages without actually telling you anything you'll be able to practically apply, but the knack of matching a mouthpiece to a sax is like mixing hot & cold water for your shower. There is one result that you like at any given time, but sometimes you like a really hot shower - and on other occasions you need a cold shower ... whether you like it or not.

Now take the shower example & think of it this way with saxophones & mouthpieces. Long ago, saxophones were built that had characteristically darker sounds with lots of tonal nuances that show through, and mouthpieces were made with large, rounded chambers that gave a diffuse, dark sound. Let's call that the cold tap, so that if you put a vintage mpc on a vintage sax you are using a cold/cold mix. Modern saxophones generally generate a brighter sound through which fewer nuances are detectable, and modern mouthpieces generally have smaller, more angular chambers that brighten the sound, and often include raised baffles that add a detectible edge or 'buzz'. That's the hot tap -- such that when you use a modern mpc on a modern sax you get a hot/hot mix. Now all you need to do is find the right temperature mix for your sonic shower. Often a modern mouthpiece will bring out a delightful edge on a great old vintage saxophone ... and equally as often, a classic Dukoff or Link will quell the zinging brightness of a newer horn so some of the fat & rich nuances show through. When you've found the sound you want the shower is perfect ... :)

P.S.: eBay is a great tool for mouthpiece experimentation - just keep the ones you like & resell the others ...