Just done tha caldon so though I would add my thoughts. We stayed one night at Etruria by the marina/ Toby pub and it was fine. Moorings before the staircase looked good by the museum. We came down from Harecastle and the moorings at Westport were popular, other than that nothing really appealed to me as a palce to stop until we got to Etruria. Although the moorings at longport looked ok.
On the caldon Personally i would not stop beyond the staircase at etruia until Milton. Although the moorings looked fine at Milton it was narrow and not the best of views etc. the best place to stop just out of stoke we felt was between the two lift bridges past engine lock which is where we stayed and was vg and a short walk to milton. However the bit prior to this between Milton and engine lock looked nice as well.
After Milton stopping points you are spoilt for choice.