It's all personal preference, we can't really know what cube you should get, and you won't really know unless you try them both. I recently bought both (I'm assuming you are talking about the DaYan Guhong (Lone Goose), if not, ignore me, I'm a complete nub haha), and in my experience the FII is much better out of the box. After breaking in, the DaYan Guhong does get better tho. Right now, the Guhong feels faster, but I get much faster times with the FII. The FII just feels... sturdier? I don't really know how to explain it. I've heard it mentioned that the FII locks up and pops a lot, but so far my Guhong has popped and locked (hasn't been dropped tho... bad joke lol) just as much as my FII. The cubies on the FII are sort of rounded, which for me makes turning much easier and smoother. Also something I've noticed with the Guhong, corners have sharp corners due to them being in thirds and if you are kind of a clumsy cuber, they'll tear up your fingers. Well, not really tear them up, but it causes some discomfort at least. There is more I wanted to cover, but I'm drawing a blank, I'll edit if I think of it.
In the end, its all your personal preference. Both of these cubes are great and are capable of world record times in the right hands.