Most of the route I followed was away from 525 and 20 simply because the route was set up by the organisers of the Trek Tri-Island who wanted to keep the 500 or so riders as much out of harm's way as possible. We took a lot of backroads and coastal routes and it was wonderful so I try and repeat those same routes when I can. It would be interesting to see some other scenic planned routes as well so I'll try and look up the route map for the TdW.