I've met quite a few other cyclists when out on my tours that have rode that route and to a man they tout it as the best 'scenic' ride one can take. What I hear is that unlike most scenic rides the Trans-Canada route is 'scenic' the entire distance... ever changing, ever surprising you around the next bend.
My son is seriously considering moving home from England in the next year or so... he also rides... and if he does I wouldn't at all be surprised if he and I don't hit the Trans-Canada Highway.