The present disclosure provides enhanced storage systems that facilitate efficient storage of, and access to, a variety of items and products. Exemplary systems according to the present disclosure include Mechanisms that permit reliable and efficient repositioning of one or more shelves, thereby enhancing utilization and efficiencies associated therewith. Shelving systems facilitate synchronized vertical motion of shelving units, e.g., based on coordinated pulley / cable systems, and advantageously include spring designs that facilitate controlled vertical motion of shelving units, e.g., based on fluid movement and / or discharge from the spring design. Shelves and / or shelving units may be readily repositioned at elbow or eye level, and repositioned at their respective initial positions in an efficient and advantageous manner. The shelving systems may be original manufacture units or may be designed for use in retrofitting existing shelving systems.