Are bike racks with sliding designs truly worth the extra cost and complexity, or are they just a marketing gimmick designed to separate cyclists from their hard-earned cash? What specific benefits do these racks offer that fixed-position racks do not, and are these benefits significant enough to justify the added expense and potential reliability concerns? Do the supposed advantages of sliding racks, such as easier bike loading and improved versatility, outweigh the potential drawbacks, including increased weight, reduced durability, and higher maintenance requirements?