Both excellent choices, but since you're asking for opinions: Both are targeted at the exact same market segment - SA/DA, double-stack, hammer fired, de-cocker. I've handled and shot both, and they have flawless function. Both are as good as it gets. Subjectively, the CZ just feels better to me. I love Sigs too, but one of my very few complaints about them is that they always seem be a bit "chubbier" than they need to be, especially in the 9mm category. Between the CZ -P01 and the Sig P229 - my opinion is that they'd be equal in the role of range and home defense guns, but the lighter weight and over all slimness of the CZ will probably make it a better choice for concealed carry.
I've always noticed something about CZ and Sig.; Sigs feel like high-end guns, and their price reflects that fact. On the other hand, CZ isn't the most expensive gun around, it just feels like it.
That's all completely subjective opinion on my part though. The good part if it is that objectively, no matter which one you buy, you can't go wrong.