The HiQ upgrade to the 3D Systems Vanguard selective laser sintering (SLS) machine incorporates a revised thermal calibration system and new software. This paper quantifies differences in mechanical and morphological properties of specimens built first using a Vanguard HS (high-speed) system and again using the same system with the HiQ upgrade applied. Standard specimens are built from DuraForm PA material and tested for tensile modulus, tensile strength, elongation at break, flexural modulus and Izod impact strength. The design of the specimen battery, the conduction of the tests and the significance of the results are discussed. The upgrade is found to reduce user intervention and total build time and improve surface finish. However, tensile, flexure and impact properties are all found to decline after the upgrade is installed.