I have no experience, but I have read that they are nice for health and good for meat production, and that they have nice temperaments. Don't know how that translates to mothering, but I was reading about Cremes just a couple of days ago, and wishing I had a nice, huge rabbitry, so I could have all the different kinds of rabbits I want... :lol:
A friend of mine from another forum (might be here too, I am not sure) used to raise them and I recall that she liked them a lot, but they gave her some trouble breeding and it was so difficult to find replacement stock, too.
I think they are beautiful- would love to have one of the endangered heritage breeds one day when we have a larger rabbitry.