The simple different between a Tactical Vest and a Plate Carrier
MOLLE real estate, with the Tactical vest, the zipper limits the MOLLE strips that encompass the vest, while the Plate carrier, have a uninterrupted strip of MOLLE so you can mount pouches any spot on the vest itself
Weight, with a TacVest, weight is next to none, due to the fact that it carries nothing, some were designed to go over a armor carrier and for speed. However a Plate carrier sacrifices speed and weight for protection, each side can carry a panel of Kevlar or a ceramic plate, weighing up to 20 pounds per plate, and gives the carrier stiffness/rigidity and reduces sagging that all vests suffer from pouches but since the weight sometime does not matter to each person, one can substitute the plate with foam
Now if you wanted a light weight, with speed in mind for CQB, I will have to put out a chest rig. Light weight but carries limited amount of pouches for spare magazines, and you might add a battle belt for even more MOLLE re-estate
