So far, I'm not all that impressed. The most powerful reaction I've had so far is that I can't figure out why SF is always derided as a boys' club, because Banks' writing style is almost identical to that of your average historical-romance author, and I found the same thing to be true of Frank Herbert when I read Dune a couple of months ago.
Behold a sentence (it's both a sentence and a paragraph, actually; it kicks off Chapter Four) from Matter:
Utaltifuhl, the Grand Zamerin of Sursamen-Nariscene, in charge of all Nariscene interests on the planet and its accompanying solar system and therefore - by the terms of the mandate the Nariscene held under the auspices of the Galactic General Council - as close as one might get to overall ruler of both, was just beginning the long journey to the 3044th Great Spawning of the Everlasting Queen on the far-distant home planet of his kind when he met the director general of the Morthanveld Strategic Mission to the Tertiary Hulian Spine - paying a courtesy call to the modest but of course influential Morthanveld embassy on Sursamen - in the Third Equatorial Transit Facility high above Sursamen's dark, green-blue pocked Surface.
Even if I manage to get past the ultra-filigreed writing, the plot is shaping up to disappoint, too. It's basically a story of betrayal and royal intrigue with spaceships, and as is so often the case with space opera SF, it takes place at a lofty remove, where the only people who've shown up so far are aristocrats and their trusted servants (living and mechanical). Nobody is shown building or repairing or cleaning or otherwise staffing the vast empire - there's a battle, and soldiers are fighting and killing and dying - just not onstage.
I hope it gets better, I really do. Because I've got 532 pages to go, and I don't just want to be entertained - I want to figure out why this guy is so revered.