Short answer
Compare shuttle and crane AS/RS against the work the system must do every day, not only storage density or theoretical capacity. In cold storage, temperature, energy, maintenance access, pallet quality, and peak behaviour always belong in that comparison.
Start with the pallet that must leave tomorrow
The comparison often starts with capacity and investment. The operation starts with the order: full pallets, part pallets, case pick, BBD rules, load sequence, and peaks that do not spread neatly through the day.
A technically elegant system that does not fit that daily mix makes work-arounds unavoidable. Those work-arounds usually become visible only when pressure is high.
In cold chain, you do not only choose a machine. You choose how the operation absorbs a bad day.
Maintenance does not happen outside the operation
In a chilled or frozen environment, serviceability is not a footnote in the maintenance contract. Access, safety, technician availability, and recovery directly determine what the operation can still deliver.
The best solution is not automatically the fastest one on paper. It is the one that remains predictable in cold, pressure, and a failure at the wrong time.
Put the same bad day next to both designs
Compare both designs on the same days: normal volume, peak volume, planned maintenance, a failure, growth, and a change in the order profile.
Then it becomes clear where extra flexibility genuinely adds value and where a simpler design is stronger. That is a much better conversation than comparing one capacity sheet.
Is the operation behaving differently from the plan?
I look at the actual flow: process, system, decision-making, and people. That is usually where the next move is.