Sabre uses a vacuum bag/divincell construction for their boats.Why do they do this and is it better? Yes, it is a better manufacturing technique to a point because it allows them to produce the same stiffness and strength but with less weight. In performance cruising, weight is the key - or one of the critical keys. This process is a more expensive, more time consuming process that creates a lot more waste and is more involved. I cannot remember if their hulls are cored above the waterline (not the deck, the hull), but it seems that I remember that being the case. If they are cored, that is a huge negative for me on a cruising boat. Now Sabre can get away with this production technique because they make a lot fewer boats than Catalina and their customers will pay for that extra performance their boats will yield. If they built to the scale Catalina does, it would be a considerably more involved and expensive boat. I would almost argue that they cannot build to Catalinas numbers as there is too much waste and involvement to make that work at scale.
Catalina’s hulls are all hand laid glass. They are not cored at all. Like Sabre, Catalina does use a lot of E and S glass in critical areas. But the ending product is that the hull is a heavier, thicker hull (I have to assume). Why do I prefer this? I prefer a solid glass, relatively thick hull because sooner or later (or fairly frequently in my case), you are going to run aground, hit something, etc. For this reason I am totally against cored hulls for cruising and it is why I also prefer a thicker, solid glass hull (to a point). I want the bulk... not Tayana kind of bulk, but a medium compromise for me. This is my preference and others are fine to disagree.
As far as the displacement of the boats... I can tell you that a C400 is nowhere near 19500 lbs. I think I measured in at 22-24ish when I bought the boat and am now at 27,500. I would be very pleasantly surprised if my 400 was foot-foot lighter than a sabre. I think the 400 would be better served trying to shave off some weight... but I don't know where they are going to do it from as (you will shortly see) my preference would be for them to do some things like Sabre that would add weight.
Tankage. I think the Sabre is very low on tankage. My 400 comes with 44G of diesel and we can easily add another tank to almost double that (if any 400 owners want to discuss this with me, let me know though I talked about it in the last Mainsheet). I like the Sabre over an IP or Tayana because I really believe they will get sailed more and are a better performing boat, but in the end, you still have to charge your batteries, run your generator, and will end up doing a LOT of motoring. That is just life. And I have frustrations with the tankage I have right now... not to talk about what I would need to do to get the thing ready to cross the pond (Atlantic). The water tankage is the same between our boats and I find that to be something less of a factor because of watermakers. I will also say that we spent ten days in the Tortugas (Wife and two kids with me) and we actually came back with some water. That included showers sometimes twice a day... so I think the water tankage is adequate, especially if you add a watermaker.