I take Spinoza's arguments against a free will to be sound. The issue is whether humans have an infinite capacity of self-determination, i.e., can function as the causal ground of action. There is a further question about whether and how this capacity or ground interacts with, or is exempt from, the natural causal order. (The rejection of free will generally rests on a rejection of the possibility of exemption from the natural causal order.)

There are some neo-Hegelians (I guess you can call them that, anyway) who have good arguments for there being such a capacity. (See: http://ndpr.nd.edu/review.cfm?id=10904 and http://ndpr.nd.edu/review.cfm?id=15445 )

But there is something to be said for the distinction between a free will and a non-free one being merely verbal. (That is, amounting to nothing more than an insistence that in ordinary parlance we should keep talking as if we have a free will even if scientific evidence points to that claim being false... this is generally what the compatibilist view amounts to... though they may disagree with such a cynical assessment.)

Anyway, it's also true that complex nervous systems generate emergent degrees of freedom, but this doesn't stem from the will, but from computational power and related powers of self- and future-representation.