The hardest time I had with any of the speed runs was Chapter 2. I ran that one too many times, even tried following Upsilon and Skyzo's videos on YouTube, but every time ended up a few seconds short. I was so happy when i finally got it done, and since I has spent so much time on it and got so many skills down, the rest of the speed runs and even the DLC maps weren't as hard. Though I will say Actino and Actino Rise in the DLC were tough as nails.. and very unforgiving. Easily my most proud 100%, just for the sheer frustration involved in it.
50k achieved 10/10/2011
100k achieved 7/3/2014
Latest: Assassin's Creed Chronicles: China