Hey Dan - we have not trekked in the Himalayas yet, so we cannot make a comparison. However, I'd be interested to hear about your stories and see your photos. Do you have a travel blog? (edit - just checked your BPL profile, which has the link to your photos. Awesome stuff!)
We hiked the Huayhuash in May. This was the start of their winter, which is also their dry season. So, the days were supposed to be clearer and the night colder, as compared with their summer. May-July is supposed to be the best time to trek in the Andes of Peru and Bolivia.