I bought a MacBook Air back in 2012 and it's still going strong, even the battery life is still good.
It's survived years of abuse being thrown around as hand baggage, been dropped many times and has even been run over by the hangar floor cleaning machine.
It's now slightly banana shaped but keeps working.
The only problem I've had is the changing cable started to fray where it exits from the charger, this has been bodged with a length of heat shrink and hasn't been a problem.
It's now been relegated to the role of office computer (to save me having to drag a computer though airport security) as I've now replaced it with a MacBook Pro. In many respects, especially the keyboard and choice of ports (USB, SD Card etc.) the MacBook Air is a better computer than the Pro.