The Links are generally easier to play. Usually, they offer less resistance and the sound that comes out is a BIG WARM sound. Links also have great dynamics.
In my oppinion, an Ebonite Berg Larsen is closer to the Link sound than a metal berg larsen. All Bergs tend to be rather edgy. and play with a Big BOLD sound. Its really for those players who just loves laying a fat sound out. Really plays with a "in your face" kind of attitude. I play a ebonite Berg and whenever I push it harder, it just performs harder and the mouthpiece has never set a limit upon me. I'm lucky to have found a wonderful Berg Larsen. The metal bergs, well, just take the big, boldness, and the full sound you get from a ebonite one, and double it.
Berg Larsens can play very softly and warm, but I find it more fun to just really lay it out when playing on a Berg, because its something I can never do on an Otto Link. I find the Otto Link to be a great piece for those songs that require a delicate and warm tenor sound. But my personal favorite is the Berg because of its raw power.