I love the name [name]Louisa[/name] - when pronounced with an “s” rather than a “z”. I’m worried however, that the “z” pronunciation may be the default for most people…
[name]How[/name] do you pronounce [name]Louisa[/name]? Also, do you pronounce [name]Luisa[/name] differently?
I pronounce [name]Louisa[/name] with an “s” sound. I must say I have never heard it said with a “z” sound!
I pronounce it with an S as well. However, there was a poll about this issue not too long ago, and most namberries voted for the Z pronunciation. I would assume that [name]Luisa[/name] would most definitely be pronounced with an S though, as it appears to be more Spanish looking.
There was a recent thread about exactly this, if you do a search.
I pronounce it with a Z sound, but it’s totally a matter of accent. My own name has this same issue, and it truly doesn’t matter to me which one people use. It’s not like lou-ee-za vs. lou-eye-za, or something like that. [name]Luisa[/name] would definitely be pronounced with an S, though. And BTW, [name]Louisa[/name] is a gorgeous name and one of my favorites! 
Thought I posted then, but I didn’t, so…
I say it with a Z. I’ve never heard the S.
I live in the Chicago suburbs and I’ve always pronounced it Luweeza.