I'm not really an authority on this but I read in some of the Zeiss literature that Zeiss use Fluoride Ions in the objective lens of the FL series. This is supposed to have the benefits of fluoride without the problems of fragility and oxygen exposure problems that pure fluoride has. I feel it is one step closer to a CA free optical system. Probably the next step will be aspherical eyepieces to get rid of the CA in eyepieces like they have done in camera lenses. The question is will people be willing to pay alot of money for maybe not a huge increase in optical quality.
Flourite isn't really that delicate. I believe that Takahashi now make 2 element APO scopes, with the outer element made from Flourite, and protected with a hard coating. Obviously if you bring in a cold scope from outside and pour hot water on the objective, it'll shatter. Canon have used Flourite in their long tom lenses for years now, and the only side effect is the need to weather seal the lens. They seem to have had no problems with deterioration of the optics.
As Deco rightly points out, Zeiss use Flouride glass, not Flourite, in the FL range.
I pretty much agree with what Walter has said. The extra Flouride glass element does IMO reduce colour aberrations to a noticeable degree. The extra clarity is probably due to the FL element, and the AK prisms. But most people don't seem to bothered by the CA in competing instruments anyway so IMO the other binoculars on the market can compete. Just look at threads on BF and you will see that many many people prefer Leica Ultravids, or Swarovski ELs, or Nikon HGLs, and the real connoiseurs opt for the Goldrings (humour intended in that last bit).
The problem is that if you improve the objectives, then you have to either increase the price, or reduce costs elsewhere. I am not convinced that Leica and others will respond in kind, though I would be pleased if they did. I don't see them introducing two lines e.g. Ultravid and Ultravid ED, as it would suggest that the vanilla Ultravid was lacking. But who knows. I guess it all depends on how we consumers respond to the Zeiss FL. If we all buy Zeiss, and wave goodbye to Leica et al, then yes they will respond in kind. The Zeiss FL seems to be doing very well, but it is not wiping the floor with the competition, assuming that the recent BF survey is indicative of the market place.
The other elements in the Zeiss FL are normal non-ED glass i.e. a crown and a flint. ED means extra low dispersion, and according to Alan French ED is the widely used generic term for extra-low dispersion glass, though Nikon also use the term in their marketing literature, and as part of the lens name. Other manufacturers use other terms. I think SD means super low dispersion (same thing), and HD, LD and APO are in effect all used to indicate the use of ED glass, or equivalent e.g. Flourite. Does it make a difference? Yes, it does improve the overall image quality. I have a Nikon 200mm AIS F4 micro lens. It is non-ED, and gives nice image quality, but it's not quite as good as the best ED lenses, such as the Nikon AF equivalent.
Leif