While I only ran once, the one thing I was very happy with was my pace, I decided to try to stick to my natural speed (that tends to be around 10 min./mile) and just stick with it. That's the speed I enjoy running the most, it comes "easy" and I did all my training on this, all the build-up to the marathon. I actually managed to keep it very well: my time was 4:31, an average 10:22 min per mile. Pretty dead on!