Ask grocery industry employees about what type of pallet is easiest to manhandle, most would likely vote for plastic. Plastic pallets are generally lighter and smoother than their wooden counterparts, but generally speaking, they come with limitations that should be considered by the material handler.
Plastic is usually considered to be less stiff as a pallet material than timber. With this in mind, one should not assume that any plastic pallet can be used for a load that is to be racked in a free span without the pallet deforming under load. Distribution pallets of the 9-leg variety are typically only meant to be loading platforms for distribution of goods to retail outlets, for example, and not racked.
Newer generation plastic pallets made by many leading plastic pallet manufacturers are now increasingly designed for racking, but this should not be assumed without checking first.
It should go without saying - do not cut your plastic pallets in half. I see this happen at retail outlets where pallets are cut in half for special displays, and it is not a good idea. Some plastic pallets have steel reinforcement bars in them, and some pallets may contain decaBDE fire retardants.