Water levels are usually acceptable around Chicagoland, though I have run into areas where I had to walk the boat when I paddled the Fox out of the Wedron area heading down to Ottawa where it meets the Illinois River. As would be expected, though there may be more water level around the suburban areas, there are far fewer intrusions by civilization in the far southern sections of the river.
Scenic value is high, especially when in areas where a forest preserve abuts the river. There are dams every four to fifteen miles, so be aware of their locations. Many of the dams have exit pads before the dam and launch pads below the dam.
The bridge in the photo below is the I-90 Tollway, and you can see a bike bridge under the bridge. A good location to put-in is Voyageur's Landing Forest Preserve on the west bank of the river.