Looking really good imo! If you wanna get some hue variation on the brick you can run the tile generator node through a gradient map. Each stop on the gradient map will create a new color variation for your bricks.
A little more work on my contest substance. @oXYnary I tried playing around with the idea of baked bricks a bit more. I'm not sure how I like them. I toned down the underlying dirt to better focus on the bricks themselves.