Ran a 20 miler today - my first run with e-Gel. I was out of town (in Chicago) all week, but I managed to get in all of my runs, so I felt ready for the run. I got a good night's sleep (Alabama won!) and woke up to 70+ degree weather and 100% humidity.
The e-Gel worked as advertised for the first 16 miles or so of the run. They have a lot more volume than any other running fuel that I have used, so that will take some getting used to. Ran with water instead of Gatorade in my Camelbak. But the heat and humidity eventually caught up with me. The e-Gel makes me more thirsty than any other fuel that I have used, then add in the weather conditions and I ran out of water too soon. The last 3 miles of the run were really bad, but I made it. Kept my heart rate low (averaged 138 BPM) but lost 6 pounds of water weight on the run even though I drank 65 oz of water - not good. That also explains why I was so light headed at the end.
I am going to use the e-Gels a few more times before making a final decision about them. Again, the size/volume was a slight problem for me, as was how thirsty they made me (drank a lot more water that I am used to drinking in similar conditions which caused me to run out of water too early in my run).