To reflect some of the weapon changes with the high definition models, new sounds were given to the shotgun and assault rifle, as well as new sprites for the game's HUD. The 9mm Pistol, originally based on a Glock 17, was replaced with a Beretta M9, and the Submachine Gun was replaced with an M4 carbine. This included some notable changes to the game's original arsenal. In addition, all of the weapon models were upgraded as well. The upgraded character models in the High Definition Pack included the scientists, security guards, and HECU soldiers, as well as several of the Xen creatures.
Consequently, while the models are improved in terms of the level of detail, it remains a matter of opinion as to whether they look better. However, despite the increased level of detail, the style of some of the models, most noticeably the HECU Marines, have been changed. The improvements coming from the High Definition Pack mainly stem from the increased polygon count over the default Half-Life models.
