Capacity and hold time are the obvious answers. The build quality you cannot see is the one that decides what it costs you over five years.
Capacity and Hold Time Are Linked
More absorbent matrix means more cold mass and longer hold, and also more weight to handle and more cost to ship. The CryoStork range runs from the V2 at 2 litres to the V10 at 10 litres for exactly that reason.
What You Cannot See
The vacuum insulation economics that apply to storage vessels apply here. More layers of multilayer insulation, cleaner internal materials, a larger getter. These determine performance in year five rather than week one, and none of them appears on a comparison table.
The Cost That Is Not the Purchase Price
A failed shipment costs more than any shipper. The variables that cause failures are charge state, hold time margin and handling, and all three are affected by build quality. A shipper bought on price alone, charged in a hurry and shipped with no margin, is the combination that produces losses. The decision framework is in dry shipper hire or purchase, and the insulation mechanism in vacuum insulated cryogenic storage tanks.
