This is like asking which child is your favorite. Unless you have only one child, it changes depending on what is happening.
Simply, horizontal carousels are the most economical. They are great for under 8 foot ceilings, they hit high productivity levels. You can change the units lengths and heights plus give you emergency access to inventory.
Vertical Lift Modules or VLMs are perfect for ceilings over 12 feet and provide the highest levels of ergonomics.
Vertical Carousels are ideal for areas under 12 feet tall and for inventory that is relatively static in size and requires emergency access to your inventory.
All three systems will save you floor space, increase your productivity and ergonomic levels. So understanding what your business model is and prioritizing your goals will impact which system is “the best” for you.
Your Sapient Automation representative will be happy to provide a no obligation analysis to determine the best system for your application and organization.