I was there 3 years ago. No problem with quito then elsewhere on the planet.
We had almost the same trip. (i think they all do the same) Cotapaxi was very nice.
The galapagos was very nice to experience, but less good for photographing.
You are only allowed a certain timespan on each island (by the minute) and not able to walk free and you have to keep up with the guide.
So to create marvalous shots at sundown when everything is perfect, forget it.