Luke ist right about the crop.
Here's a summary of what Mr Baud writes about the two varieties:
Sultane has been cultivated in the Provence region of France for a long time and is also called 'Grosse de Juillet', 'Noire de Juillet' or 'Bellone bifère'. The first crop is early, in July (hence the name), the figs are nearly black, red inside.
The main crop is from about mid-August to October, with smaller figs of about 1,7 ounces.
Its growth is vigorous and bushy, it produces side branches very easily. The terminal buds are dark red, very characteristic.
Its taste is good, but I think, Ronde de Bordeaux is said to taste even better.
Ronde de Bordeaux ressembles Sultane as far as its vigorous growth and side branches are concerned. The main crop starts early
in August.
Both varieties are fairly hardy. Ronde de Bordeaux is perhaps better for colder climates, because its one and only crop is
on the new branches, therefore it doesn't really matter if there is any frost damage on last year's growth. (After a mild winter there can
be a tiny amount of breba fruit, but not really interesting for its quantity.)
Hope this helps, too.
Lilli