I love both versions and can't quite decide between them. I think the lighter version is perhaps marginally easier to read, but the dark version makes a great impact.
My only niggle would be with the light-coloured labels. I find them a little hard to read, and I think the colour doesn't blend well with the rest of the map. To me, it sticks out like a sore thumb. I understand that you might want to draw special attention to those places by using a different colour and font, but I feel it doesn't quite succeed.
For what it's worth, I'm new to map-making, but have a little experience with web design. I was taught that a design 'no-no' was using two similar - but slightly different - font styles on the same page, as the styles clash. So, for instance, a serif and a sans-serif font together are fine, as they provide a nice contrast to each other, but using two serif fonts that look broadly similar was bad form. I understand the rules for maps are probably a little different, but when I look at your map, I see two clashing script fonts. I love the black-coloured font, as it's clear and easy to read, and works well with the style of your map, but the other font is just too similar. It doesn't contrast, it only clashes, and it's harder to read too. My suggestion would be to use the same font throughout, but you can provide contrast by varying the size, colour, or perhaps letter thickness if a Bold/Heavy option is available.
Those are my thoughts, take 'em or leave 'em!