I got him! Finally! Gosh, and I was totally not expecting it. I was tabbed out, watching some CSI and saw the screen flash. I got a heart attack when I saw the little spinning picture of Aeonaxx and started looking around Quartzite basin for him like a maniac. He was at the other spot, just outside of the temple, but he was VERY high up. Closing the gap between him and me was like years! I screamed when I mounted him, and took about a minute or so to get him down but I was shaking like a leaf, only managed to get 1 screenshot in combat amidst all the excitement!
The wait and all those hours finally paid off!