Great feel, but high maintenance costs

Love the soft deck and cushy feel of the Life Fitness. However, after buying a "commercial" T9i in 2003, we had to have the motor rebuilt in 2007. Our $5,000 treadmill does NOT have a reversible deck, so we're facing $500 in deck and belt replacements every 3 or 4 years. The heart rate monitor hasn't worked right since the motor rebuild. Perhaps the belt and deck replacement might help our current motor problem - the treadmill stops after 20 minutes of running at high speeds.