In reply to petegunn:
Cheviot to Windy Gyle is mostly on flags as it the Pennine way, after that its 85% peat bog sinking sometimes up to your knees. Best time to walk it is when its -5 and frozen solid and you can walk over the top! Today might have worked actually! Usway and Harthope Burn are OK'ish for water unless after rain, depends on your definition of clean! Steep parts of Hedgehope and Cheviot are OK but like I say anywhere flat is a bog. Your route sounds like somewhere you would take the wife if in the middle of a messy divorce. Mind you at least I can say "see I'm not the only one who's been there"