I found this review of the Pen y Fan race from Anthony Clarke, a novice fell runner and self-confessed "plodder", who ran in 2011 and 2012 and described his experiences eloquently with profile and speed graphs.
You can see Anthony's results here, confirming that he improved a lot second time around.
http://www.breconfans.org.uk/Results?race=PEN+Y+FAN&year=ALL&sex=ALL&club=ALL&cat=ALL&name=Anthony+Clarke
Hope we'll see you in 2013 Anthony - you could definitely get under the hour!