This is my favorite part of the naysayers argument. Last I checked airplanes do not take off and land at "altitude". What is the MOST dangerous time frame for any aircraft flight 99.9% of the time? Take off and landings. Climbing to altitude, power up for a go around/aborted landing, etc. Those are at low altitude for the most part. So lets run a fuel that is suspect at lower altitudes. Poppycock!!!