I'm not a local so only basing it on the following, but I walked out to Bramley-Moore Dock from the Echo Arena yesterday having been up for the game on the weekend. Would agree with those so far: it took me 35mins or so at a relaxed to moderate pace. There was also no smell whatsoever (first thing I checked after some of the comments on here in relation to the sewerage works).
Would also agree with one of the posters earlier, there is little to nothing there for the 2nd half of the walk so they will definitely need to build some facilities out there nearby. Was like walking through a ghost town at times with all the (seemingly) abandoned buildings.