I don't own a Concept, but I've been using them for about 4-5 years now. I've had them with me in Afghanistan and Africa (some extreme conditions at both place and the machines were in tents with exposed ends. i.e. the machines were exposed to climate) and they have all functioned great.

I can't even remember one breaking at either location. The ones in the base gyms I use get heavy traffic and I never see any under repair.

Thinking about getting one myself to keep at home.

Jer