I loved the trip on the Izta. I head problems sleeping in the hut due to the height. But finally (with the help of an Aspirin :-) i managed to sleep a few hours and get up to the top the next day. I can really recommend this trip.
did the first paraglider flight from the summit by myself
I started from the microwave station/tower, traverse west on one of the lower trails below the false summits until Ayoloco hut. From the hut, ascend straight up to the summit. Roundtrip from microwave station: 9 hours.
As with most people, this was our first experience with altitude above 15,000ft. What I would do if I was to do it again would be this: Spend the night at either Paso de Cortes, or La Joya. We stayed in Amecameca, & then early in the morning got a ride to the trailhead (La Joya), then hiked to the Esperanza Lopez Mateos hut. The next day only 2 out of 5 of us were able to reach the summit. This was nothing more than a high altitude hike, but respect the altitude, especially if it's your first time. Once you reach the knees, the angle lessens, but there are many false summits. It was a good experience.
My first "big" mountain was Ixta. Fairly straight forward climbing. A few areas required scrambling. No crampons or ice axe needed. To my surprise and delight I had absolutely no problems with altitude.