I have some opinions on that, but for the purposes of the story, I agree that the level of superiority of Solaris's intelligence is pretty much beside the point (or rather, the futility of attempting to parameterize Solaris's intelligence is the point). Maybe it's not even self aware. Maybe it's hyperintelligent but reaches conclusions in geologic time, or something. Maybe it's amused by us and would find the notion of communicating with us in a meaningful way silly.
On the topic of self awareness vis-à-vis aliens, Peter Watts' Blindsight is a recent classic.
Another fantastic book on the subject His Master's Voice, where a whole massive team of scientists tries to decode an interstellar signal. In the end, they didn't even prove it was a signal, and not a natural phenomenon.
Also - The Invincible. Probably the most western sci-fi styled book among his works, dealing with an interesting concept of mechanical evolution.