NordicTrack A2250 Treadmill Review

First off, I'm a big guy at 250.  But I'm a runner, not a jogger.  I average 25-35 miles per week and only run on my treadmill when I cant run out side.  When I run on it I generally do speed work for 30 minutes, anywhere from a 7.5 mph run to 9 and 10 mph sprints (the max speed on this machine).  I had enjoyed it until recently when I noticed it seemed to have a dent in the running board.  upon further investigation I found a board of MDF which was almost split trough.  This is after only 166 miles on the machine.  I can't believe they use MDF first off, and second I was told that this was a medium duty machine, i.e. for heavy home use not quite fitness club quality but good enough.  I will contact the company to see if I can get replacement parts for a reasonable price but I am very disappointed in the A2250 treadmill for the use of substandard parts.