I cycled the Cheshire ring clockwise last year, starting in Northwich, and really enjoyed it. I had an overnight at a b&b in Marple. The terrain is really varied, ranging from quality paved paths to muddy, overgrown, gnarly towpath. I used a hardtail 29er, and was glad of a bit of suspension to take the sting out of the rough bits, of which there are plenty. I made the mistake of thinking that, as it is following canals it will be easy. The trouble is at least 50% of the distance is like riding over a ploughed field.
The parts through Manchester are interesting, the tow path was closed round Whitworth Street, so ended up on the busy city streets, but nothing to daunting, and the urban areas of east Mancheter are certainly places you don't see in tourist guides.