I don't like leg split dresses but what would put me off that dress isn't the split so much as it's an odd thing to do with a dress in that material and print.
It's as if the designer thought well this is a pretty dress, but it's a bit conservative so let's sexify it up by splitting the seam. I'd like it more with the seam sewn up, but that's just me. Presumably OP likes the split look. I wouldn't worry about it being windy. Even if it were the dress won't blow up that way as its quite fitted at that part of the body.