I do not have specific experience with those lenses on the 900, but I have a Fuji A20x8.6BRM on my 900. Even though this is an industrial piece of glass it's fairly new and I think may be cleaner than some of the older broadcast lenses I've worked with in the past. Perhaps the newer glass has been produced with newer technology and exacting standards? Either way I've decided to hold out for a piece of HD glass. Unless the added throw is an issue, it's a great deal, or there is another issue as to why you are looking to change, you might consider holding off.
In all I don't know that you'll see a giant difference, but be sure your lens set-up is correct for any glass you consider so that you're comparing apples to apples.