This is excellent information. I will almost certainly use it if we get to Ecuador with enough time left on the trip to trek around the Quilotoa loop. It's high on my list, but we have limited time, and Ecuador is the final stage, so might get moved to a future trip. But great info all the same!
Oh, and for further info, I use AlpineQuest on my mobile phone, and find it absolutely fantastic as a cheap GPS app. Obviously not comparable to a separate dedicated GPS, but can download maps in advance, load a vast range of tracklogs, and it graphs some fun statistics such as average speed (and more useful: altitude) over time. I used the free version first, but the paid version is worth it. To make your phone last almost as long as a dedicated GPS, download the maps in advance, and then switch off all antennas (except GPS, of course. Airplane mode works well for this, and then switch GPS on again manually). Dim the screen so you can just see enough to undim it in bright sunlight. So far I have gone 4 days with my phone as a GPS (although I did switch it off for some stretches). Under intensive screen use, in horrid misty conditions in rocky terrain with no clear trail, I have gone 2 days. Under "normal" city use, my battery lasts less than 24 hours.