Floor mixers are so named for two reasons. One, they are too big to sit on a countertop. Two, they have large capacity bowls that, when full of dough or sauce, will be too heavy to lift onto a counter, so the bowl is kept as close to the floor as possible to facilitate easy use. The bowl capacity for floor mixers ranges from 22 quarts to over 200. One mixer can usually accommodate a few different sized bowls if you have differing capacity requirements. Bowl adapters are also available. You may also want to consider a bowl truck for employees to easily move large, heavy bowls to and from the machine.
Other than bowl capacity, transmission type is another important consideration when selecting a floor mixer. Most are either belt or gear driven, and each type has its advantages and disadvantages. Belt-driven models tend to have variable speeds, so you can easily transition to a higher beater speed and reduce product splashing. However, belts can wear out over time and will have to be replaced.
Gear-driven transmissions should never wear out and have to be replaced because the gear housings are usually permanently sealed and have the sufficient amount of grease to keep things functioning properly. One drawback is that gear drives tend to have fixed speeds, and there is always that small jolt or splash of product when switching to a higher gear. The manufacturers often argue that these units are stronger, but that is debatable.