I go with [sænz] in an English context, or, if I'm feeling particularly elegant, [sɑnz]. Of course, the French pronunciation is arguably more correct, as it is a French word. However, it's been accepted into English with an English pronunciation in other contexts as well.

Josh

Is it a French word? Usage of "sans" in English goes back to Shakespeare, at least.

Is it a French word? Usage of "sans" in English goes back to Shakespeare, at least.

The language in which Shakespeare wrote owes a great deal to the influence of Norman French on Old English. And, the OED says the preferred pronunciation of insouciance, a pure borrow from French, is the Anglicized pronunciation, so go figger...

The OED has an entry for "sans" where "sans pareil", "sans cérémonie" etc are mentioned, but there is a separate entry for sanserif, where there is no reference to French. Since I see "Calluna sans" as an abbreviation for "Calluna sanserif", I see no reason to make it sound French.

I'm sure it varies by region, but here on the US West coast saying "saw sayreef" would brand you as eccentric or pretentious, unless you were trying to get a laugh. I can only recall one person, a client, trying it and it became a joke around the office.