Power supply over voltage... some units permit this to be trimmed (field adjusted)...
A lamp batch -- presumed to be Chinese mainland -- economic pressures and rapid supply expansion means that quality control is an after thought...
Plainly, he's running his spots at FULL POWER. Most owners do not. Cutting them back, even a tad, can have an amazing impact on lamp life.
He's not permitting human skin oils to get all over the lens faces is he? Be sure to wipe them down with isopropyl alcohol -- preferably the 95% stuff sold at electronics stores.
