If I had those choices for my DS at your DD's age, there's no question i'd go with the unstructured place at least for the first year of preschool. My DS does not particularly like conforming. And we've been pretty unstructured with him all along. But once your DD gets closer to "real school" you may want to find a place that offers at least some structure so she'll know what's expected in school. But in our experience, 2 years of fairly structured preschool (those mostly play-based), has been overkill.

Sorry I can't help more - what does your gut say?