In the - shall we say - mid-early period of rock and roll sax, say the early 60s to the early 70s, the Berg Larsen was pretty much the standard for rock tenor players. At the same time, jazz players were approaching a lot of the rock style in a lot of ways. A whole lot of players took up the Berg at this time.
Dukoff came out with his mouthpieces maybe in the early 70s but they really hit big in the late 70s. A whole lot of players took those up. Although Dukoff made several designs, the late 70s/early 80s rock tenor sax standard setup was the Dukoff D7 or D8.
Now the Berg and Dukoff design concepts are quite different. The Berg is what we would call a "small chamber" - squeezed on the sides and with baffles of varying height but none of them a lowish rollover baffle like you see on a Link. The Dukoff is a fairly large chamber - same size as the cork bore - and a high baffle that drops off fairly early.
I haven't played a lot of Bergs but when I have, I haven't got on with them at all well. I can't explain exactly what it is I don't like about them but they seem real resistant to getting any sound out. On the other hand the Dukoff (and I've played a few other pieces of similar design) blows real easily for me, but I do have to be careful to support the airstream enough to get some thickness in the tone. It can turn shrill and ducky otherwise. I think that the Dukoff and the Link/Meyer pieces I favor, respond somewhat similarly in many ways.
Lots of other folks have the opposite reaction - hate the Link/Meyer/Dukoff response type, love the Berg response. My favorite story, which I'll inflict on you now, is when I used to go over to a buddy's house and play along with Aebersolds with him. We were both playing tenor, me on my old #8 Meyer and him on a rubber Berg (I don't know the spec). Just for fun, we interchanged the two mouthpieces. All I could get out of his Berg was a couple sad little moans and he couldn't get anything out of my Meyer at all. Switch back and all was as it was before, both of us getting normal decent tenor sounds out of our horns. Point of the story: it's all individual, a combination of your own conformation and what you're used to.