Worth noting here is that the approximation factor here is 5500. (I.e., the algorithm is only guaranteed to return a route whose length is no more than 5500 ti

Worth noting here is that the approximation factor here is 5500. (I.e., the algorithm is only guaranteed to return a route whose length is no more than 5500 times that of the optimal route.) Much bigger than 3/2! But apparently it's the first polynomial-time constant-factor approximation algorithm at all for it, so...