http://www.sfreviews.net/mainspring.html
Money shot:
"Mainspring is a grand and glorious adventure, an epic journey of imagination the likes of which I haven't often seen... a breathlessly exciting tale that takes the best old-school storytelling and the most vivid contemporary world-building sensibilities and spot-welds them together. Think Edgar Rice Burroughs or Philip José Farmer meets China Miéville or Ian R. MacLeod, by way of religious allegory. Mainspring is always gripping and often dazzling in its vision."