No one can deny that the south-east of the country is really very pleasant, both from the point of view of its landscape and the friendliness of the local population. Vilcabamba is certainly the most touristy spot, but its gringo, neo-hippy atmosphere is not everybody's cup of tea...
Zamora is a pretty little village that is less popular, at least among foreign tourists. The main reason for stopping there during your trip to Ecuador is to discover or even bivouac in Podocarpus National Park. Of course, the city is also known for its clock, which is the largest in the world (its needle is over 11 metres in length); but I am not certain that this detail is enough to justify the visit...
It's worth noting that the ecosystem of the park mentioned above is so rich that it is considered as the botanical garden of the Americas. Waterfalls, mountain streams, butterflies, centuries-old trees, hummingbirds: it's magical. With a Special Mention in my opinion for the beautiful Poderosa waterfalls.
Apart from that and the pleasant climate, there is not much else to be said about the city. Be that as it may, I really enjoyed my visit to the region and highly recommend it!